A man is to stand trial in Seattle this week accused of 48 charges of murder.
Mr Gary Leon Ridgway (54) is expected to admit being the Green River Killer - named after the river south of Seattle where the first victims were found.
Mr Ridgway, who has been married three times and is the father of a child, is expected to plead guilty to all of the charges, sources have said. If he does so, he will have more murders on his record than any other serialkiller in America's history.
The pleas will spare him the death penalty in King County, and assure him life in prison without parole, the sources said.
However, two of the bodies on the official list of Green River victims were found in Oregon, which has capital punishment, and it is still unclear whetherMr Ridgway will plead to those.
The remains of scores of women, mainly runaways and prostitutes, turned up near ravines, rivers, airports and roads in the 1980s. Police officially listed49 women as probable victims of the Green River Killer.
Mr Ridgway, who was arrested on November 30th, 2001, had been a suspect since 1984, when the boyfriend of missing woman Marie Malvar reported he last saw her getting into a pickup truck identified as Mr Ridgway's.
But Ridgway told police he did not know Ms Malvar, and a police investigator in Des Moines who knew him cleared him as a suspect.
Later that year, Mr Ridgway contacted the King County Sheriff's Green River task force - ostensibly to offer information about the case - and passed a polygraphtest.