POSSIBLE "GREEN RIVER KILLER" SAYS 13 "YES", 15 "NO WAY"

TACOMA, Washington - Robert Lee Yates, who has already admitted murdering 13 people, is fighting for his life as he goes to trial for two additional killings.

Yates, 50, has confessed to 13 murders dating to 1975. Ten of the dead were Spokane-area women involved in drugs and-or prostitution who disappeared in 1996-98. The other three were a couple and a woman killed elsewhere in the state.

In exchange for a guilty plea two years ago, Yates was sentenced to 408 years in prison rather than the death penalty.

But Pierce County prosecutors refused to sign off on the plea bargain. Former prosecutor John Ladenburg was "adamantly opposed" to allowing Yates to bargain away the death penalty.

Like the 10 Spokane women killed in the same period, Mercer and Ellis were killed with a single gunshot wound to the head. Like most of the Spokane victims, their bodies were left in remote areas, their heads swaddled in plastic garbage bags.

Yates' DNA was found in semen samples retrieved from Mercer, and Ellis' blood was found inside a van he owned.

In both cases, forensic scientists found bullet fragments and matched them to a .25-caliber Raven model semiautomatic pistol. Court documents showed Yates owned two pistols of that caliber and model.