DNA-The Molecular
Profile of a Criminal
This is a very large article but once you have read it, you
will understand most if not all you will need to know about how DNA
solves crimes.
Convicting a
criminal without an eyewitness has always been chancy and sometimes convicting
someone on the testimony of an eyewitness has been even more risky. In 1903,
when fingerprinting was first recognized in the United States, it was recognized
as being an infallible way to get a conviction because
the ridge arrangement on every finger is unique in the sense that no two
persons have ever had the same fingerprints unless they are identical twins.
But many
rapists and murderers didn't leave identifiable fingerprints on their victims
bodies so detection became almost impossible. Then along came laser
fingerprinting and the prints of the assailants were detected on skin, and that
helped convict some, but not all.
But if
these criminals didn't
leave their fingerprints behind, almost all of them left
their semen inside the bodies of their victims. A large number of these
criminals were convicted on the testimony of forensic scientists who were able
to testify as to whether or not the blood type detected in the semen was the
same as that of the accused. But
detecting criminals this way was not
always a sure
thing because 20
percent of the human population
are not secreters. A secreter is someone
whose blood type can be determined by analyzing that person's body fluids-such
as his semen.
Human blood
falls into four main types. They are, O, A, B and AB. The breakdown between the
four are best explained this way: Out of every 18 persons in Canada, 8 are
blood type O (obviously the most common) 7 are blood type A, (a close second) 2
are blood type B and only 1 is blood type AB.
Just suppose
that in North Sidney, Nova Scotia, a small city of 7500, a man raped and
murdered a woman and left his semen behind. The investigators could narrow down
the suspects in the following manner.
First, they could rule out the females. That would cut the odds down to
3700 male suspects. Then they could rule out the boys under 16 and men over
65. That would reduce the odds to 1800.
And let's suppose that the murderer was a secreter and his blood type was AB.
That would leave 100 possible suspects. And suppose 90 of them had an alibi
that was satisfactory. That would leave 10 suspects in which one of them probably
raped and killed the woman. I used the word probably because up to
recently, all the police would have at this point in their investigation would
be scientific proof that any one of the 10 suspects could have committed the crime,
but could have is
not enough to
secure a conviction.
And suppose her estranged
boyfriend had blood
type AB and he couldn't account for
his whereabouts on
the evening in
question. Would that narrow it down to one? It would certainly be good odds that he was
the murderer but if that was the only evidence the police had, those odds of 1
out of 10 is hardly the kinds of odds a jury would want to convict someone on.
DNA identity
has arrived and it is a method in which the identity of a rapist who leaves his
semen inside his victim, can be determined with as little as a 1 in 30 billion
to 4.5 trillion chance ever being wrong.
When you realize
that ever since
the beginning of time, there has been no more than 78 billion people on
this earth, you can really appreciate these odds. To understand this
highly complex method
of analyzing the suspect's semen to the nth degree, one
must first understand what DNA really is.
DNA
abbreviates the word, 'deoxyribonucleic acid' and is the cell substance in each
of our individual cells that acts as a blueprint for our individual genetic
information. Each one of our cells has exactly the same DNA in it so that the
DNA in a cell taken from our hair or bone is no different than that taken from
our blood, or in the case of males, from their semen.
As the
rapist ejaculates into his victim; as
many as 400 million of his sperm enter her vagina (or elsewhere) and with his
sperm—the DNA genetic code that can identify him. The head of each sperm is
stocked with enough DNA in it so that in terms of genetic information, it would
be possible to fill dozens of Encyclopedia
Britannicas sets with all that information.
There are
over 200 billion cells (to twice that number for the obese) in each human being
and yet DNA is so small, that if it were possible to collect all of the DNA of
every human being in the world today, (6 billion of us) all of our DNA could be
placed in an eye dropper.
Coded in the
DNA are the complete instructions on how every cell in the body should be
built. Of course, DNA is also found in the mother's egg and therefore her
heritage is passed on, along with the father's heritage, to the offspring. If
the DNA segment that produced brown hair in one parent matches up with the DNA
segment that produced
red hair in
the other, the offspring will have brown hair. If the
father has long eyelashes and the mother, short eyelashes, the offspring will
have long eyelashes. DNA fixes the amount of earlobe sagging, and decides the
width of the ear and the shape of the folds.
Everyone of
us has about 200,000 useful control genes in our DNA. It is easy to calculate from skin rejection rates between blacks and whites, how many
of them control skin colour differences. There are only four. That means out of
200,000 genes, 199,996 will be left to determine the shape of our heel bones,
the width of the main arteries to our livers, the arrangement of nerve cells in
our brains ad infinitum. One could go on
and on about just how much the DNA in our cells determines the structure of
every part of our bodies but it is suffice to say that all of us are different
(with the exception of identical twins) because of the DNA makeup in the cells
of our bodies. If a rapist leaves his
semen inside his rape victim, (or for
that matter, even one of his hairs or his flesh or blood under his victim's
fingernails) he is in effect, leaving behind for the forensic scientists to
discover, his indistinguishable DNA
fingerprints—the blueprint of his genetic makeup.
It was Alec
Jefferies, a geneticist at the University of Leichester in England who in 1983,
discovered this breakthrough in genetic 'fingerprinting' as a criminal
investigative tool. Using bacterial enzymes as chemical 'scissors', he cut the
DNA taken from several people
into segments and
arranged them into patterns that looked somewhat like
enlarged bar codes found
on supermarket products. Since each DNA 'bar code' was uniquely
different, he had no trouble in ascertaining which 'bar code' belong to which
person after he compared each 'bar code' with the others. At that time, it took
two weeks to process a sample.
In 1983, a
15-year-old girl was raped and murdered near the English village of Enderby.
Her murderer was not found. Then in
July of 1986,
another 15-year-old girl was
raped and strangled in the same
area. Soon after that, a 17-year-old youth was arrested in connection with the
second murder. It was about this
time that Alec
Jefferies had come
up with his
DNA fingerprinting discovery. His
technique of analyzing the nuclear DNA (as apposed to analyzing the mitochondrial
DNA) clearly showed
beyond any doubt
that although the same man killed both girls, the 17-year-old youth was not
the man they were looking for.
The police
decided to ask the 5500 men in the area to submit to blood tests for the
purpose of determining which of them had the exact DNA 'fingerprint' of the man
who murdered the two girls. All of them gave samples of their blood—all accept
a 27-year-old baker called Colin Pitchfork. He asked a friend of his to donate
his own blood and to say that he was
Colin Pitchfork. The friend later blabbed what he had done in a pub and shortly
thereafter, the baker was arrested. He gave a sample of his blood and the
comparison was made. His 'bar code' matched that of the murderer's blood on the
two victims and he was convicted and sent to prison for life.
This raises
an interesting legal issue. Can a suspect be forced to submit to having a
sample of blood taken from him for the
purpose of determining
if he is
the guilty party? The Supreme Court of Canada came down
with a decision in December 1988, that fingerprinting suspects who have not
been convicted of a crime is not an unwarranted invasion of privacy. The court
said that ‘a person who is arrested on reasonable and probable grounds that he
has committed a serious crime must expect a significant loss of personal
privacy.’ Justice LaForest who wrote
the decision of
the Court, said
that fingerprinting suspects
charged with an offence does not violate the principles of fundamental justice
(if) police have reasonable and probable grounds to believe an offence was
committed.
But keeping
in mind that fingerprinting suspects is not the same as inserting a needle into
their arms for the purpose of drawing blood, it does not follow that this
decision is carte blanche authority to hold a murder suspect down and stick a
needle into him. However, this
possibility may come about in the future if one of Justice Jeffries statements
is taken to the nth degree. He said
in the fingerprinting appeal;
“It must be remembered that
the interest of the public
in law enforcement
necessitates the subjection
of the individual
to other distasteful procedures.”
The police
can ask a doctor to take a blood sample from an unconscious driver to determine
BAC reading of a patient if the police obtain a search warrant to do so. It may
be a big leap from taking blood from unconscious persons to taking it from
conscious uncooperative suspects but considering the importance of DNA
'fingerprinting' as an investigative tool, that leap may end up at the end of
this century as a mere hop, skip and a jump.
DNA
fingerprinting is being used quite extensively by the Americans. For example,
in 1986, a Florida court convicted a man on
two counts of murder and necrophilia and in the same year, a U.S. military
court in South Korea sentenced
a serviceman to 45 years for rape and attempted murder.
Both men were
convicted as a
result of DNA
'fingerprinting' techniques. In Wetchester County, N.Y. as many as 200
DNA fingerprinting specimens were
presented to the
district attorney for evidence but most never went to trial because when
the defendants saw the evidence, they pleaded guilty.
There have
been some vast strides made in this field and scientists have devised an even
more sensitive technique and have
used it to
classify samples containing
less than one nanogram (1 billionth of a gram) of DNA.
In fact, they can work with specimens as
little as a
single DNA molecule.
Their method relies on a molecular copying process called 'polymerase
chain reaction gene amplification', which has been steadily changing the face
of molecular biology ever since it was invented in the mid-eighties. While traditional methods of copying genes or
proteins for which they obtain the code, takes several weeks,
the newer
method thus described can produce millions of copies in less than a day.
It is
conceivable that before this century is finished, a single strand of hair taken from the clothing
of a victim, or a minute sample of the rapist's sperm may yield such
information as race, colour of skin, hair and eyes, and whether or not the
criminal
being sought is large boned or small boned. Such information might even go so
far as to state whether he or she has long eyelashes. By putting that
information into a computer, within seconds, the actual suspect from the files
of known and past criminals may appear on the computer screen. No doubt, DNA 'fingerprinting' babies
at birth will
be acceptable (just
as footprinting them now is) and if this is so, that information will be
placed in a master computer and when the identity of a missing person, an
unidentified body or a crime suspect is needed, the authorities can go directly
to their DNA 'fingerprint' computer files and within seconds, have the name
(and probably the picture also) of the person they want to identify. That's not so far-fetched as one might think.
With the new
computerized techniques that are developed where missing children can be
'aged' on a computer for future identification purposes, it is conceivable that
in the future, the information obtained from one nanogram of DNA can be placed in such a computer so that
investigators will be able to create a
likeness of a suspect.
Determining
both paternal and maternal parentage is becoming relatively easy now
that DNA 'fingerprinting' has
been discovered. In one case, a
Ghanaian boy born in England
emigrated to Ghana
to join his father. When the boy tried to rejoin his mother back in England , the
authorities suspected that a substitution had occurred and refused to admit
him. DNA fingerprinting determined that the boy was indeed related to his alleged mother,
and the authorities
permitted his immigration.
This method
of identification is presently helping to identify missing children and victims
of disasters and is useful in the research of genetically inherited diseases.
Sherlock Holmes was great in his day with his magnifying glass in hand, but
with the advent of spectroscopy, (instrument used to analyze the molecular
structure of evidence left behind in a crime scene) forensic scientists were
able to zero in on criminals, but with the discovery of DNA 'fingerprinting',
it's beginning to make spectroscopy look like Sherlock Holmes with a magnifying
glass in his hand.
On October 12,1989, a 69 year old Nova Scotia woman
was brutally raped. The police knew the identity of the man who committed this
heinous act. He was even convicted of the crime and given a 6 year prison
sentence. Fortunately, a semen sample had been recovered, and a state of the
art DNA test had been performed. It proved conclusively that Josh Borden was
the rapist. But an appeal court threw the case out because of the way the
police had obtained the DNA sample from Borden, despite the fact that the
chances of it being wrong are about 1 in 10 million. The prosecutors were not
allowed to use this overwhelmingly conclusive evidence because of a
technicality which protects the offender.
The elderly lady who was in her bed in a senior
citizens' home was sexually assaulted and her life was threatened. She was
unable to identify the man because he had held a pillow over her face. A couple
of months later another woman was assaulted. Borden was identified and arrested
for this second crime.
The police asked him for a blood sample. Borden gave a
DNA sample for that offence, and only that offence. The police, who also
suspected him of raping the first elderly lady, compared the sample to the
semen sample taken from that case. The samples matched. Borden was convicted of
the sexual assault of the first elderly woman. However, Borden appealed and the
court threw the case out of court because Borden had not been asked to provide
a sample for the first crime. The sample was only for the second assault. The 4
year sentence for the second assault is almost up, and soon Josh Borden will be
free to walk our streets.
WHAT IS DNA?
DNA testing, which stands for deoxyribonucleic acid,
is essentially the ability to determine a person's biographical fingerprint.
Analysts test the highly distinctive strands of the DNA in a sample to
determine its origin. Like fingerprints, no 2 people can have the same DNA,
save perhaps identical twins. It is estimated that the chance of this kind of
evidence being wrong is 1 in 10 million. There are several means of obtaining
DNA samples. They are:
- blood - this is the most common sample that is
tested; it can be tested whether it comes in the form of liquid or a stain
(however, the material the stain is on can be a factor, i.e. jeans are not good
but cotton is); only a small sample is needed; - hair - the sample needs to be taken from the root, and about 10 samples are
usually required; - semen - most commonly found in cases of sexual assault
taken from bed sheets or underwear; only a small sample is required; - saliva;
- bone (marrow);- flesh; - urine; and nteeth (pulp).
Samples up to 5 years of age have been tested. DNA
evidence can provide more definite and objective proof of guilt or innocence
than can often be provided by eyewitness identification or other such
subjective means.
DNA AND THE LAW
As is too often the case in Canadian criminal justice
history, legislators are too busy catching up to tested and accepted law
enforcement techniques to keep up with them. In this case, the technique is DNA
testing. Canadian police have been at the forefront of the development of DNA
testing in criminal trials. The RCMP opened a national casework service in DNA
Typing at the Central Forensic Laboratory in Ottawa in 1989. Yet police and the courts had
little to no guidance from the legislature concerning DNA until 1995.
On June 22, 1995 then Justice Minister Allan Rock and
then Solicitor General Herb Gray announced amendments to the Criminal Code and
the Young Offenders Act that would facilitate the police's role in obtaining
DNA evidence. Bill C-104 was proclaimed as law which now permits a judge to
issue a warrant allowing police to obtain bodily samples from suspects for forensic
DNA analysis. The legislature clarifies the circumstances where the court can
be permitted to issue a warrant, the procedure under which suspects can be
compelled to provide samples, and how those samples will be taken.
ISSUING OF A WARRANT
DNA is an incredibly powerful revolutionary weapon in
the war on crime. Search warrants for DNA samples may prevent future injustices
like that of the Borden case. Such search warrants are not much different in
theory than obtaining breath or blood samples from a person whom the police
have reasonable suspicion to believe may be driving while impaired.
In order for a judge to issue a warrant, a police
officer must show that there are reasonable grounds to believe that the suspect
committed any one of a list of designated offences such as: first or second
degree murder; manslaughter;
assault, aggravated sexual assault, assault causing bodily harm or sexual assault with a weapon, threats to a third party or causing bodily harm, sexual interference, invitation to sexual touching, or sexual exploitation.
assault, aggravated sexual assault, assault causing bodily harm or sexual assault with a weapon, threats to a third party or causing bodily harm, sexual interference, invitation to sexual touching, or sexual exploitation.
EXECUTION OF THE WARRANT
There are three "investigative procedures"
authorized under the legislation for the collection of bodily substances. They
are as follows- the plucking of individual hairs from the person; - the taking
of a buccal swab; and the taking of a small quantity of blood by pricking the
skin surface with a sterile lancet.
DESTRUCTION OF DNA SAMPLES
The legislation contains strict rules governing the
destruction of samples taken from a person for forensic testing. In order to
protect the privacy of the person, samples of substances seized under the
authority of the warrant that remain and the result of the analysis must be
destroyed if: the involvement of the suspect in the commission of the offence
has been disapproved, the information is withdrawn,
if the prosecution is stayed and not recommenced; or if the accused is finally acquitted.
if the prosecution is stayed and not recommenced; or if the accused is finally acquitted.
It is important to note that this new legislation can
be used in the investigation of offences committed prior to the coming into
force of the Act.
DNA APPLICATIONS
DNA has various uses. For example, it was recently
used in Ottawa
to identify 2 identical twins who had been adopted and accidentally separated
at birth. It can identify parents of children in paternal matters. But its use
in the criminal justice system may be the most powerful, and also the most
controversial. Some of the applications of DNA in law enforcement are:
- In violent crimes, hair, blood and semen samples are
more common than fingerprint evidence. This is especially true for sexual
assault cases. Such evidence would make investigations go much quicker. It
would not only help implicate the guilty, but it would eliminate the innocent,
thus sparing them the pain and embarrassment of being a suspect (it is
estimated that more than 35% of the cases received by the FBI result in the
exoneration of the accused). it would allow the police to set up a data base
which could include all DNA of convicted sex/violent offenders (see the section
on databanks for more information).
DNA evidence could be used to help identify a murder
weapon. For example, a knife with blood stains could be tested against the
victim's DNA. DNA evidence could be used in homicides, sexual assaults,
assaults, hit and runs, etc. DNA could be used to distinguish "copy
cat" crimes from serial crimes. DNA could connect crimes committed by the
same offender, i.e. serial murders. DNA could determine if more than one
offender was involved in a particular crime. DNA evidence could identify deceased/missing
persons.
A study done by the British Columbia RCMP is an
excellent example of how effective DNA evidence could be. They have 45 unsolved
murders and over 20 unsolved sexual assaults (with DNA evidence), plus several
other serious violent offenses in which DNA evidence was available. If, based
upon reasonable grounds, police suspect a particular individual committed the
crimes above, they will now be able to ask a judge for a warrant to gather DNA
from the suspect. If the DNA matches, the cases will be prosecuted without the
offender ever having to speak a word.
THE LEGAL QUESTIONS OF DNA
EVIDENCE
The legal question of taking a blood sample from an
accused person who does not consent is a critical issue. Is it a form of
self-incrimination, or does it constitute an unreasonable search? The answers
are not clear. When people are pulled over on suspicion of impaired driving,
they are required to give a sample of their breath. Could this not be
considered to be a form of self-incrimination? If the suspect refuses to give a
sample, he/she can be charged. A warrant can be issued for that person's blood
if that person is suspected of impaired driving (if they cannot give a breath
sample).
However, the more serious a crime is, the heavier the
sentence and the greater the stigma. Therefore, the courts may be more
stringent on the issues of constitutional rights. For example, it is less
serious to be convicted of drunk driving than of murder, so the courts may be
more protective of an accused person's rights if the charge is murder. This is
ironic considering that the majority of the public might think it is more
important to put murderers in prison than it is to put drunk drivers in prison.
Another issue in DNA search warrants is the
determination of a standard or threshold of proof to justify the taking of a
sample from an accused. The standard for an officer to get a breath sample from
a person he/she believes is driving while impaired is reasonable and probable
grounds. For example, an officer may see some erratic driving, smell alcohol on
the suspect's breath, etc. But, DNA testing is more complicated, and may
warrant a higher standard. Defense lawyers are concerned that the police will
test everyone until they get a match. While this is far fetched, the question
of how much proof is enough must be addressed.
When people are arrested, they are required to undergo
fingerprinting. This evidence can be used against them, for example to compare
evidence found at the crime scene. The Supreme Court of Canada, in 1988, said
that the fingerprinting of a suspect not yet convicted of a crime is legal, and
is not an unwarranted invasion of privacy. The court said,
“A person who is arrested on reasonable and probable
ground that he has committed a serious crime must expect a significant loss of
personal privacy.”
In R. v.
Alderton, the accused was convicted of sexual assault. He appealed that
conviction. The assailant was reported to have worn a nylon stocking over his
head during the attack. The officer in charge of the investigation, Detective
Ashton, observed some hairs on the nylon stocking that had been left behind by
the offender. He wished to compare those hairs with the hairs of the accused.
He told the accused that the hairs could be given freely or they could be
taken. The accused agreed to give them. Ashton produced a brand new comb, and
ran it through the hair of the accused, and the accused also plucked some
hairs. Alderton is appealing that the hair evidence should not have been
admitted because it violated s.8 of the Charter (search and seizure). The court
said,
“It is settled law that following a valid arrest a
police officer may search the person arrested and may seize anything that he
reasonably believes will afford evidence of the commission of the offence.”
In this case, Detective Ashton had reasonable grounds
to believe that the analysis of hair samples from the appellant would connect
him with the offence. The taking of the hair samples was not accomplished by
violence or threats of violence...did not contravene s.8 of the Charter."
In R. v. Legere,
the appellant was convicted of second degree murder for which he received a
life sentence with no parole for 18 years. The case involved the savage beating
of an elderly couple in which the man was killed. A sample of hair was found at
the scene of the crime. The police, after a discussion with the Crown Attorney,
decided to obtain a sample of Legere's hair. Four officers went into Legere's
cell (he had been arrested a short time before) and requested some hair
samples. He refused. The officers then began pulling hair from his head. The
accused then did it himself. Six days later, the police returned with a warrant
for the purpose of obtaining more hair samples. The accused did not consent,
but he offered no resistance. The hair was needed to place the accused at the
scene of the crime. At trial, the Crown conceded that the warrant could not
authorize the taking of the hair in that way. The court did find that the
samples were taken without consent which is forcible taking of parts of a
person, in the absence of legislation authorizing such acts, is an infringement
of the right to security of the person and constitutes an unreasonable search.
However, the judge said that the admissibility of the
hair samples did not bring the administration of justice into disrepute, and
therefore the evidence should be allowed. It seemed that the judge was sending
a message to legislators to pass some laws concerning future situations like
this.
DNA has been used in Canadian courts. For example, DNA
testing was allowed in the case of R. v.
Parent (1988). Parent had been accused of committing 11 sexual assaults.
The Crown believed that all of the attacks were committed by the same man. The
attacks were all very similar except for one. DNA evidence was introduced, to
which neither counsel objected. However, the DNA tests cleared the accused of
several of the assaults. He was convicted of the 1 count that differed from the
rest.
DNA evidence was also used in R. v. McNally (1989). The accused broke into the home of a 68 year
old woman and sexually and physically assaulted her. She identified him in a
police lineup. He pleaded not guilty, and provided a sample of his hair, blood
and saliva. The DNA results of these samples were then compared to those of
semen found on the bedspread and nightgown of the victim. The judge ruled that
such evidence was admissible because it was no different than fingerprint,
blood or fibre evidence. After a recess, the accused pleaded guilty and received
7 years.
In R. v.
Baptiste (1991), on the question of the admissibility of DNA evidence, the
court said,
“Should DNA evidence, because it is relatively new, be
treated differently? I think not. If in that the experience in Great Britain,
United States and Canada is now sufficient to say that the science of DNA
testing is reliable and that where it is relevant and would be helpful to the
jury, the evidence should be admitted.”
In reality, the police have had to resort to some
pretty imaginative means to try to get DNA samples from suspects, from
obtaining a tissue that an individual has used to blow his nose and thrown away
to retrieving shed hair. They have also tried to use the common law power of
search incident to arrest but with varying success. This refers to the right of
the police officer to search an individual upon an arrest. The problem is that
this power of search is mainly for the purpose of determining if the individual
has any weapons.
An example of a case where the police had to resort to
undercover techniques to get a DNA sample is the Ryan Love case. Lucie Turmel, a 23 year old taxi driver, was
stabbed to death in Banff .
The murderer left his blood smeared inside the cab. The police, using DNA
testing, tested samples from a number of people who all gave samples
voluntarily. No one matched. They then got a tip on 22 year old Ryan Love. He
was asked 4 times to give a sample, and he refused each time. Therefore, two
police officers went undercover and befriended Love over the course of one month.
They posed as petty criminals and committed bogus robberies with Love. During
the course of the month, they obtained a hair sample which was suitable to test
for DNA and a tissue that Love had used and discarded. Love's DNA matched and
he was arrested and charged with murder. His lawyer argued that Love had been
the victim of an unreasonable search, and therefore the evidence should be
ruled inadmissible.
The judge disagreed and allowed the evidence saying
that the violation was trivial in comparison to the possibility of allowing a
murderer to go free. Love was found guilty of second degree murder and
sentenced to life in prison with no parole for 20 years.
INTERNATIONAL
EXPERIENCE WITH DNA EVIDENCE
In 1983, in the English county of Leicestershire, a 15
year old girl was raped and murdered. Her killer was never caught, but semen
was recovered. In July, 1986, another 15 year old girl was raped and murdered,
and another semen sample was obtained. A 17 year old boy, Richard Buckland, was
arrested for the second murder, and he confessed. DNA tests showed that the
same man killed both girls, but Buckland was not that man (Buckland became the
first murder suspect in the world to be exonerated by DNA evidence). The police
then asked the 5500 men in the area to give a DNA sample. All of the men gave
samples except for a man named Colin Pitchfork, who asked a friend to go in his
place. The friend told other friends what he had done, and it worked its way to
the police. Pitchfork was subsequently arrested and he confessed to both
murders. He is serving a double life sentence.
The Americans use DNA testing extensively. In the late
1980's, 200 DNA fingerprinting specimens were given to the District Attorney in
Westchester County , New York . Most of these cases never went to
trial because the accused persons pleaded guilty after seeing the DNA test
results. As of January 1, 1990, DNA tests had been admitted into evidence in at
least 185 cases in over 35 states. It is estimated that these tests have been used
in over 2000 cases, in over 45 states.
The FBI began accepting cases in December, 1988, and
reported its first case in March, 1989. By July, 1989, they had received over
2600 samples for over 535 cases, and by February, 1990, they had received over
6375 samples for over 1335 cases. They estimate that they can process about
10,000 samples a year.
The first case in the United
States to use DNA was Florida
v. Andrews in which the accused was convicted of over 20 cases of sexual
assault or attempted sexual assault. DNA tests have been used successfully in
cases where the death penalty was given. There have even been cases where the
accused requested a DNA test only to have it reveal his guilt.
POSSIBLE PROBLEMS WITH DNA EVIDENCE
Critics of DNA worry that the police may over rely on
DNA evidence. In arguing their point, they raise the following problems that
can arise with DNA evidence.
Contamination problems include; heat and humidity.
These factors can harm samples. Moisture and high temperatures are the most
damaging. Other factors include post-mortem samples: state of decomposition,
time since death, temperature where body was stored. All of these factors can
affect testing.
Not all of these tests results indicate a
"yes" or "no" answer. Therefore, these tests should not be
interpreted to prove guilt especially in sexual assault cases. It must be
remembered that not all males are secreters (about 20% are not). Therefore, the
absence of semen does not mean that there was no sexual assault. In many
homicides, samples are not available and in many rape cases the only issue
before the court is consent.
Other complaints about the use of DNA in the criminal
justice system are its great cost and time consumption. Even if a case is high
priority, it can still take more than 3-4 months to be completed. The cost of
equipment and staff and time are very expensive. But are we willing let money
stand in the way of such a valuable investigative aid? What is the cost of not
having this evidence? We need only to look to B.C. for the answer. DNA evidence
has the potential to save lives by putting murderers and rapists in prison, and
it can keep innocent people out. Can we really put a price on something so
valuable?
In July of 1996 Mr. Justice Archie Campbell released
his recommendations resulting from the Royal Commission into the Bernardo
Investigation by various police forces in Canada. In his conclusion and
recommendations, he found that " Bernardo's 1990 DNA sample went into a
'black hole' for more then two years, during which time he killed two teenaged
girls Leslie Mahaffy and Kristen French, as well as raping four others.
"In hindsight, it is clear that these rapes and murders could have been
prevented if Bernardo's DNA had been tested earlier." Campbell recommended that all DNA samples be
tested within a maximum of 30 days. This sent shock waves through the
scientific community as well as the RCMP, who operates one of the only labs in Canada . The
government became concerned over the need for more technicians, as well as the
very severe financial cost of scientific equipment needed for the labs. The
financial burden upon the government thought may be a necessary for long-term
savings.
When one factors in the time that police spend
investigating a suspect and observing his/her actions; DNA may actually save
money. If the police have a suspect, like in B.C., where they do not have
enough evidence to press charges and must put the suspect under surveillance,
DNA could quickly tell them if they have the right person or not.
DATABANKS
As mentioned earlier, there has been much discussion
about the development of a DNA databank. The DNA of convicted sex offenders and
other violent offenders could be stored into computers which would then be
accessible to police forces across Canada . It could provide the
ability to do split second searches and comparisons. It would be similar in
theory to the Automated Fingerprint I.D. System that is currently available to
police. Police forces are able to do a 3 minute scan of millions of prints.
Databanks will assist the police in 3 areas:
1. open cases - police could make searches to
determine if cases are connected, and they could test a suspect's DNA against
that in storage;
2. missing persons/unidentified deceased victims - DNA
could make the identification of these people much easier; and
3. convicted offenders - those convicted of violent or
sex offences would have their DNA stored on the computer, and this could cut
down on the recidivism rates by having new crimes tested against those in the
computer.
In Canada ,
it was recommended by the Campbell Commission in 1996 that the federal
government take steps to build a DNA databank to keep information and DNA found
at crime scenes to assist in prosecution, as well as linking offences that may have
been committed by the same offender. In September of 1997, Solicitor General
Andy Scott announced that a federal databank designed to hold DNA concerning
offenders would be in place within the year 1999. This databank, located at the
RCMP headquarters in Ottawa ,
would enlaced DNA samples of offenders convicted of serious crimes, as well as
DNA profiles of evidence from the scenes of unsolved crimes.
Over 20 U.S. states have already adopted laws to
require testing for some group of violent offenders, and several other states
are proposing legislation. DNA results are relatively easy to store in a
computer. In fact, the FBI has developed computer software for this purpose. It
is hoped that databanks will have an impact on recidivism rates. Released murderers
are 5 times more likely to be arrested for murder than are other offenders, and
released rapist are 10 times more likely to be arrested for sexual offenses
than are other criminals. It is estimated that 60% of offenders who commit 3
violent offences will re-offend, and 80% of offenders who commit 4 violent
offences will re-offend. Every time a convicted pedophile re-offends, it costs
over $200,000 to prosecute, imprison and treat him/her. If offenders know that
their DNA is in a police computer, they may think twice about re-offending.
There are several civil liberty issues surrounding the
use of databanks. For example, there are concerns about what information will
be stored, which offences require an offender to be in the computer, who will
have access to the information, and for what purpose. All of these issues need
to be addressed.
THE NEED FOR DNA TESTING STANDARDS
Because the results of DNA testing can be so
powerfully convincing, and they often are the main reason for convictions, it
is important to ensure that such tests are done correctly. DNA testing in
general seems to have been accepted by courts as reliable evidence, but there
have been specific cases where the tests were not done correctly and the
results were not admitted as evidence. Standards need to be set for procedures
used, lab performances, accurate record keeping and the storage of the samples
for future testing (if necessary). Legislators and professionals should
determine these standards together.
There are 2 particularly interesting American cases
which highlight the need for DNA testing standards. The first case is People v.
Castro. The accused had murdered his neighbour and her 2 year old daughter.
There was a blood stain on his watch that matched the victim's blood. The court
allowed the evidence that the blood was not his, but not the evidence that it
was the blood of the victim. The court said,
"However the DNA identification evidence of
inclusion was deemed inadmissible, since testing laboratory failed in several
major respects to use generally accepted scientific techniques and experiments
for obtaining reliable results..."
The accused pleaded guilty in the end.
The second case is State of Minnesota v. Schwartz. The accused was
charged with the first degree murder of a stabbing victim. The court rejected
the DNA results because they questioned the reliability of the results.
"While we agree that DNA typing is generally
acceptable, we nevertheless believe the reliability of the tests results is
crucial. Cellmark (the man who performed the tests) did not meet all the
minimum guidelines...the FBI likely would not consider the tests ready for use
in court."
These 2 cases illustrate the need for universal
standards for DNA evidence.
CONCLUSION
DNA has the potential to save lives. The time to act
is now. Laws must be drafted as soon as possible so that no more innocent
people are raped or murdered simply because the police are not permitted to do
their jobs. The rights of the offenders have outweighed the rights of society
for far too long. There is no justification to not allow a technique which can
do so much good. DNA is a reality, and it is a part of the criminal justice
system. It must be allowed to reach its full potential - to exonerate the
innocent and implicate the guilty. The U.S.
has already dealt with the issue, and the UK is in the process of drafting
legislation.
This evidence will make rapists, murderers and those
who defend them very nervous as they are the only ones who oppose such
legislation. And it will make law abiding citizens breathe a little easier
knowing that the Josh Bordens of this world are off the streets and in prison where
they belong. Critics argue that if the police have the power to demand a DNA
sample, Canada
will become a police state where citizens live in fear. Many citizens already
live in fear, but not of the police. DNA legislation will not affect the
majority of Canadians who do not rape and murder—only those who do.
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