Activity
In this exercise, you will learn the basics of DNA
fingerprinting and consider the use of DNA in criminal investigations.
Part 1.
Use your browser to go to NOVA’s web site about
“Killers Trail,” the story behind
the man who inspired the Fugitive TV series and later the movie version
starring Harrison Ford:
Click on the “Chronology of a Murder” section and
read about the events that led up to the murder trial of Dr. Sam Sheppard.
1.
In your opinion, what role (if any) did
newspaper stories and editorials have in the outcome of the original trial of
Dr. Sam Sheppard?
1.
In my opinion the rle of newspaper stories
and editorials played a major part in the outcome of the original trail of Dr.
Sam Sheppard. Because of the pressure the police and jury felt from the attacks
from the media, they unlawful arrested Sheppard just to please them. The media
complained or questioned something they did what they could to please them.
Even if it ment putting an innocent man in jail with out a proper trial.
Go back to the Killers Trail homepage and select
”Create a DNA Fingerprint.”
Read about the crime and the suspects then go on to
part 2. Answer the following questions about the technique as you go through
the simulation:
2.
What is the function of the restriction
enzymes in DNA fingerprinting?
1.
The restriction enzymes work like scissors to
cut the long DNA molecules at different locations. Where the enzymes ut depends
on the code within the DNA molecule and the code within the enzymes.
3.
What is the function of the agarose gel electrophoresis step?
1.
Acts as a molecular strainer, allowing
smaller pieces of DNA to move through more easily than larger pieces.
4.
Why is a nylon membrane used to blot the DNA?
1.
The DNA is sucked into the membrane as liquid
traveled up from the gel toward an absorbent material that was placedover the
membrane.
5.
What does a dark spot on the X-ray film
indicate?
1.
Your fingerprint
Part 2.
Use your browser to go to Frontline's "What
Jennifer Saw" at
The material on this site is about a man convicted
of rape but later exonerated by DNA evidence. To read a summary of the case,
choose the link to Ronald Cotton's wrongful conviction, then choose
"Summary of Cotton's Case."
In the interviews section, read the interviews with
DNA expert Peter Neufeld and lawyer Barry Scheck.
Answer the following questions:
6.
What evidence was initially used to convict
Cotton?
1. A photo identification
was made by one of the victims.
2. A police lineup
identification was made by one of the victims.
3. A flashlight in Cotton's
home resembled the one used by the assailant.
4. Rubber from Cotton's
tennis shoe was consistent with rubber found at one of the crime scenes.
7.
What did the DNA evidence show?
1.
That Cotton was not the rapest and that
another inmate in prison for similar crimes had committed the rapes. He ven
addmitted it to another inmate but the superior court refused to alow known to
the jury.
8.
How could DNA fingerprinting be used to
prevent a false conviction if a case like this was being tried today?
1.
DNA fingerprinting gives us hardcore
edvidence on weather or not someone committed. This way those who are innocent
won’t be put way for something they didn’t do.
9.
What percentage of convicts are unjustly
convicted of sexual assault cases, according to Neufeld and Scheck?
1.
25%
10.
The O.J. Simpson trial was one of the most
visible trials that attempted to use DNA evidence. In the end, the DNA evidence was not satisfying to the jury,
who acquitted Simpson. What do
Neufeld and Scheck believe about the impact of the O.J. Simpson trial on the
use of DNA evidence?
1.
They talked about how though DNA helps in
keeping innocents from being wrongflly convicted they can still be wrong, but
it depends on if the person working on it makes a mistake.