In 1982 the first murder was committed, and over the next 19 months many other murders were committed. The victims were strangled and then dumped in ravines and near highways around the Green River in Washington. The unknown serial killer was dubbed "The Green River Killer". Most of the victims were prostitutes and runaways. Soon authorities released the names of the 49 victims believed to be murdered by this serial killer, though some of these on the lists were only missing and presumed dead.

In 1984, Gary Leon Ridgway was named a suspect, based on the fact that he had been seen with one of the victims right before she went missing. No evidence was brought up against him though. In 2001 DNA samples linked him to four murders, and he was arrested. In 2003 he was charged with three more murders. In November 2003, Ridgway confessed to 48 murders, his confession being part of a deal to save him from the death penalty. 42 of the murders he confessed to were those on the list of 49 put forth by the police earlier, and he also confessed to six other murders not listed.

It is known that Ridgway led prosecutors to three bodies he had dumped. It is believed that Ridgway murdered as many as 50 people, possibly more. Most of his victims were females who he picked up and strangled.