One of the most notorious and frightening serial killers in history was known as The Green River Killer, a moniker derived from his dumping his victims, mostly prostitutes, along the Green River near Seattle, Washington. Between 1982 and 1991, nearly 50 murders were attributed to the killer. The task force assigned to the cases developed a long suspect list but had no conclusive evidence that implicated any of the men.
One of the intriguing things about this case is that it parallels the advances in DNA technology and is proof positive that if DNA samples are properly collected and stored, they can remain useful for decades.
On April 8, 1987, police executed a search warrant on the premises of one of the suspects, Gary Ridgeway. After obtaining evidence items from his house they requested that he undergo a polygraph, but Ridgeway refused. They then asked for a saliva sample and Ridgeway complied by biting on a small, square surgical gauze.
Unfortunately, the semen samples taken from some of the victims were too small for the then available testing procedures. Using them would have consumed the entire sample, and if no match was found, there would be no crime scene material remaining if another suspect was later identified. So, the samples, as well as Ridgeway’s saliva, were stored.
In the mid-1990s, DNA testing made a quantum leap when the combination of STR and PCR analysis appeared. This new technique allowed for testing very small samples and by 2001 it had become a proven and widely available technique.
In that year, the lab tested Ridgeway’s saliva sample, obtained in 1987, with semen samples taken from Opal Mills, Marcia Chapman, and Carol Christensen, all killed in 1982 or 1983. Using the new PCR/STR technique, the samples were amplified and compared. A match was made. Gary Ridgeway was arrested and charged with four of the Green River killings. The case took a dramatic and controversial turn on November 5, 2003, when Ridgeway pleaded guilty to 48 murders in exchange for a sentence of life without the possibility of parole, thus sparing himself a possible death sentence. Many involved in the case felt that Ridgeway’s victim list was much longer.
Now a new victim might have turned up. A skull was found in a ravine near Auburn, 25 miles south of Seattle, an area where the remains of Marie Malvar, another Ridgeway victim, were also found. Dental records revealed the skull was that of Rebecca Marrero who disappeared in 1982. Many involved in the case felt that Marrero was probably a victim of The Green River Killer, but Ridgeway could never supply enough information to prove that one way or the other.
Since Rebecca Marrero was not included in the original plea bargain, will we see Ridgeway charged and tried for her murder? Could he get the death penalty he avoided in 2003 after all? One can hope. We’ll see.