Green
River Killer
Case
Study #4- Serology
Leslie
K. Penny
Chancellor
University
Abstract
The following essay
gives a brief yet detailed description of the circumstances surrounding the
Green River Killer beginning with the disappearance of more than several dozen
women to the eventual discovery of their bodies littered like trash in various
areas of King County, Washington, as well as in or around the Green River. At the time of the discovery of the bodies,
serology testing wasn't as up to par as it is in this day and age but samples
were taken anyways in hopes of more accurate testing in the future. Eventually, that time came in 2001 where a
saliva sample that was taken more than a decade prior was compared against
several of the victims vagina swabs leading to a DNA match confirming Gary
Ridgway had conducted the murders of almost 50 women. What little information could be found
concerning the testing used to analyze the DNA samples is presented in the
essay including how it affected the outcome of the case.
Green
River Killer
It started in 1982, the disappearance of women in King
County, Washington. Not a handful but,
shockingly, dozens of them. Over a time
period of roughly 20 years the disappearances turned into found murder victims,
49 in all that officials are aware of, who were believed to be victims of the
so-called "Green River Killer".
The victims, who had evidence of a sexual encounter, were murdered and
discarded like trash in wooded areas in isolated parts of King County and along
the Green River. The victims ranged from
in their teens to late 30's and were working as prostitutes giving the Green
River Killer or, accurately known as, Gary Leon Ridgway, easy access to his
victims and the thought that no one would notice them missing (Maleng,
2012). Eventually, Gary Leon Ridgway was linked to
those murders through DNA testing which were used to gain a confession and an
eventual plea agreement.
Even though numerous amounts of evidence were recovered
over the years, serology technology still had a ways to go in the 1980's,
therefore, the case remained unsolved until early 2001. At one point, in 1983, Ridgway became a
suspect in the disappearance of Marie
Malvar (Maleng, 2012). A witness stated
a truck similar to his was scene on the night she went missing but since the
witness couldn't I.D. Ridgway and there were no evidence to link him, they had
to let him go. After that he was questioned
several times as more women continued to disappear but there still was no
concrete evidence to link him to the missing women. During a search of Ridgway's home, one
detective had the mind set to take a DNA sample from Ridgway by having him chew
on a piece of gauze providing a saliva sample (How DNA Works, 1994).
Even though detectives now had a sample of Ridgway's DNA,
the semen samples taken from the victims were too small at the time, in 1987,
for testing to reveal a match. From then
on the case went cold for 14 years, (Investigation Discovery, 2012) until technology
could catch up with the samples taken from the victims. During this time period forensic scientists
were advancing in their testing technology.
By the early 90's, DNA typing became available but only with large
samples, therefore, they could not even compare blood types which was what was
available at the time.
By 2001, technology had grown so a Detective assigned to
the case submitted many semen samples taken from the victims to WSPCL for DNA
typing (Maleng, 2012). "They combined
two different types of DNA tests, the short tandem repeats test (STR) with
polymerase chain reaction (PCR), which enabled them to amplify the samples and
compare them, (Investigation Discovery, 2012). In the case of Carol Christensen, forensic
scientist, Jean C. Johnson, analyzed a vaginal swabbing that had been taken
from Carol which proved the DNA was consistent with that of Ridgway's DNA (Maleng,
2012). That was just one example that matched Ridgway
to a victim, there were scores more.
Now, with concrete evidence to link Ridgway to several
of his victims through DNA testing, he was charged with their murders and plead
guilty in 2003 to 49 murders. Instead of
going to trial he was offered a plea agreement where he would plead guilty to
"seven charged accounts and to forty to forty-seven additional counts of
murder in exchange for the prosecutors agreement to forgo the death
penalty" (Maleng, 2012). He
accepted the agreement and remains in prison until his natural death.
In conclusion, this case exhibits the importance of
serology testing. No matter how many
years it took for technology to catch up, Gary Ridgway's DNA left on and in his
victims were the main evidence used against him in the investigation and plea
agreement. The DNA in question were
semen collected from the victims compared to a saliva sample taken from Ridgway
well over a decade before it could be used against him. The facts of the case were presented as well
as the evidence pertaining to serology, mentioned above. The testimony and testing used by forensic
scientists linked Ridgway irrefutably to his victims leading to his confession
of all the murders.
Reference
How DNA works. (1994). Retrieved from True Crimes & Justice:
http://www.karisable.com/greenriverdna.htm
Investigation Discovery. (2012). Amazing Cases.
Retrieved from Investigation Discovery: http://investigation.discovery.com/investigation/forensics/amazing-cases/amazing-cases.html
Maleng, N. (2012). Prosecutor's summay of the
Evidence. Retrieved from The Seattle Times:
http://seattletimes.nwsource.com/news/local/links/ridg_summary.pdf
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