Now Playing
Cleared by a Machine: The Polygraph That Kept Ridgway Free
Audio is available on Spreaker — see link below.
In 1984, the Green River Killer passed a polygraph test — and investigators moved on, leaving Gary Ridgway free to kill for nearly fifteen more years. This chapter reveals how a single flawed result, a stored DNA sample, and the deliberate targeting of vulnerable women combined to make one of history's deadliest killers almost impossible to catch.
Audio is available on Spreaker — see link below.
Before nineteen eighty-four, Gary Ridgway was a suspect. After nineteen eighty-four, he was a free man.
By April of nineteen eighty-three, the Green River killings were already the largest murder investigation in the country. The King County task force had a two-million-dollar budget and a list of suspects that kept growing.
The polygraph examination came in nineteen eighty-four. Ridgway was still considered a prime suspect.
After the polygraph, the killings appeared to slow. By the mid-nineteen eighties, the pace of new victims being discovered dropped.
Three years after the polygraph, investigators came back to Ridgway. New information.
There's another dimension to why the investigation stalled as long as it did, and it has nothing to do with the polygraph or the technology gap. Ridgway chose his victims deliberately.
The break came in two thousand one. DNA technology had advanced to the point where samples that were previously unreadable could now yield definitive matches.
By June of two thousand three, the legal process had reached a calculation point. Prosecutors had enough to pursue the death penalty.
Despite the cooperation agreement, not every victim was found. Ridgway's memory, whether genuinely poor or deliberately incomplete, had gaps.
One last thing worth sitting with. Gary Ridgway killed at least forty-nine women.
Chapter summary auto-generated from the verified script. Listen to the full episode for the complete content.