FREE ESSAY ON DNA

DNA

DNA evidence is extremely helpful in criminal trials not only because it can determine the
guilt of a suspect, but also because it can keep innocent people from going to jail. The
suspect must leave a sample of their DNA at the crime scene in order for testing to
occur, but DNA can be found in the form of many things such as semen, blood, hair,
saliva, or skin scrapings. According to Newsweek, "thousands of people have been
convicted by DNA's nearly miraculous ability to search out suspects across space and
time… hundreds of innocent people have also been freed, often after years behind
bars, sometimes just short of the death chamber" (Adler ). Though some may think it is a
waste of time to go back and attempt to release convicts from prison after they have been
in jail for such a long time, but since DNA testing had proven to be quite a successful
method of doing this, it could help in many ways. First of all, if a person is not guilty
of a crime they are in prison for committing, they have every right to attempt to prove
their innocence. A great advantage to releasing these innocent people from prison is that
they allow for more room in prisons for those who are actually guilty of the crimes. 
Another reason people may object to DNA testing in the courtroom is that the tests
require the suspect to provide a sample of his own DNA. The only problem with this is
that sometimes, suspects refuse to donate their DNA for testing. In a situation in St.
Petersburg, FL, a man was being followed because he allegedly matched the description of
a man who was suspected of committing fifteen robberies and two rapes. As the police
followed him on his motorcycle, he stopped at a red light and spat on the ground. As soon
as the police saw this, they got out of the car and collected the saliva with a paper
towel. The DNA from the saliva was a perfect match with the DNA from the semen collected
from the rape victims. Puetz, the investigator on the case defends the constitutionality
of his evidence-gathering methods; the courts, he says, have held that once you've put
out your trash, you've waived your right to keep the contents private, and "I don't see
why the same wont hold true for saliva."(Adler).
Because there are many different types of crimes, it is often difficult to find enough
physical evidence to convict a person. For example, in rape cases there is usually only a
small amount of physical evidence, so cases are based on word alone. Because of DNA
testing we can now take samples from the victim and attempt to match the results with
those of the suspect. Therefore, DNA is sometimes the only real way of determining the
guilt or innocence of a suspect without having any witnesses. Since many rape cases are
left unsolved, DNA testing is believed to be the most accurate way of keeping sex
offenders off the street. Because of the growing trend of using DNA in rape cases
especially, a company in Brooklyn now advertises a small flashlight-like device intended
to be used to jab at attackers in order to collect a sample of his skin for later use
(Adler). According to a study by Joseph Peterson, with the Department of Criminal Justice
at the University of Illinois, DNA evidence does not have a major impact on the decision
to either convict or acquit defendants, but weighs heavily on sentencing, and often leads
to more severe penalties (Peterson, Banbury Report).
Some may think that DNA testing in rape cases, especially in the case of incest, is not
totally valid because the samples of semen, or other bodily fluids may be contaminated
with the DNA of the victim, which would produce different results. In cases of incest,
DNA could be so alike because of heredity that the results may be hard to distinguish
between the victim and rapist. Though many people believe this to be true, in all
actuality "each person's DNA typing pattern is different and virtually unique."(Genetic
DNA Typing). 
As well as placing a suspect at a crime scene, DNA tests can also be performed if there
is no suspect. DNA from the crime scene is collected, and the results are run through a
series of indexes known as the CODIS system. This system contains the DNA profiles from
other convicted criminals and sex offenders for the specific reason of finding matches in
cases where no suspect is found. "By the summer of 1999, the 99 labs using CODIS had made
218 forensic hits. Thus, CODIS matched one or more forensic profiles to an offender
sample… As a result of these CODIS hits, the participating laboratories aided 578
investigations." (Loftus).
The main reason DNA evidence should be admissible in courtrooms because it is the most
accurate form of evidence. Samples may only be admitted into court as evidence after they
go through a series of steps to make sure the evidence is relevant to the case and will
help the jury or judge reach a verdict. The judge must decide if the test is accurate by
the Frye rule, and can withhold the results if he thinks the test will confuse the jury.
The Frye rule is "the law's traditional yardstick for determining admissibility of
scientific evidence, (with) directed attention to the general acceptance of a technique
within its particular scientific field" (Shultz, Billings). In order to introduce DNA
evidence into a case, the judge analyzes the privacy that may be invaded by testing. The
five factors which are analyzed in order to introduce genetic evidence are "1) the
seriousness of the need, 2) the intrusiveness of the technique, (3) alternative methods
that are less intrusive, (4) reliability of the instrument, and (5) capacity for
limitation and control" (Westin, Banbury Report). 
The most important reason DNA testing should be used in criminal courts is that is the
most accurate form of evidence available. Because DNA testing is simply another form of
fingerprinting that is more detailed, there is currently no other method of
identification that is as technologically advanced, with as small a rate of inaccuracy.
Though there is a small chance of producing false evidence, with the ever-changing
techniques, genetic specialists are able to test more sections of DNA at a time, which
will produce a better "picture" of the DNA strands. In the future it may get so detailed
that we will be able to recognize actual features and ethnicity from DNA combinations;
this is why the term "DNA fingerprinting" is not the most accurate way to describe the
technique. It doe not lead to the identity of a person unless there is a sample with
which to compare it. Scientists are in the process, however, of developing databases
where every person will have a sample placed. Until then, however, statistics are used in
order to estimate the number of people who could possibly carry the combination of DNA
strands that match a sample given for testing "Like everything else in the scientific
world, nothing about DNA (profiling) is %100 assured"(Problems with DNA Fingerprinting).
Errors are very rare, and preventable because the statistics used to calculate the
probability are said to be the most accurate way at this time to determine the actual
number of matches that could be possible. In order for the DNA test to be admissible in
court, the probability of a match must be very low to keep from accidentally placing a
person at the crime scene when he or she was actually not. All the scientists are trying
to do is to improve the chances of a match. Using more probes and testing more sites are
helping keep the mismatches out of the lab. For example, if eight sites are tested rather
than the usual six, the probability of a match will go up. In order for the jury to grasp
the concept of testing, the statistics must be high enough for them to interpret.
Appropriately, 1 in 1,000,000,000 would be more powerful than 1 in 10,000,000. . Because
the jury is not as knowledgeable to the subject of DNA testing, it is necessary that when
presenting evidence, that the numbers used in court are ratios using numbers that the
typical person could understand and comprehend. 
Though it is hard to determine how powerful DNA testing could be in the future, it is
obvious that it is the most accurate and conclusive form of evidence available at this
time. Some believe though, that DNA tests take away the defendants rights to a speedy
trial. In some cases, where testing may take months because of its complexity, this is
true. But in most cases testing can be performed in a matter of weeks or even days
depending on the number of tests to be performed. In any case, the future should be
prepared for the ever-changing technology of DNA testing and welcome it warmly. It is
helpful and has helped in many cases that would have otherwise gone unsolved. As John
Adler stated in a Newsweek report, "DNA typing is a tool with vast potential, but only if
it is used wisely, with an awareness of human nature---the kind you don't need an
electron microscope to see" (Adler).