TACOMA - Convicted serial murderer Robert Yates Jr. is expected to be one step closer to his death sentence on Friday, when a hearing is set for the judge to sign Yates' death warrant.

Yates, 55, just arrived in Tacoma from Walla Walla on Thursday morning in preparation for the hearing to move his death sentence along.

He is facing the death penalty for the murders of two Tacoma prostitutes, whom he shot and suffocated by tying plastic grocery bags over their heads.

The capital punishment comes despite the fact that Yates escaped the death penalty in Spokane County for the murders of 13 other women in Spokane, Walla Walla and Skagit counties. Yates made a plea deal in Spokane County - but no such deal in Pierce County.

Last fall the state Supreme Court upheld the death sentence in an 8-1 ruling, and a Superior Court judge is expected to sign it Friday, setting the date 30 to 90 days out. But the prosecutor says it probably won't be carried out yet.

"It's my prediction that the state Supreme Court would stay the execution," said Pierce County Deputy Prosecutor Jerry Costello.

The legal reason for that is because Yates is likely to file a 'personal restraint petition' asking the court to review additional matters that were not reviewed during the direct appeal, Costello said.

"And I'd imagine the Supreme Court will grant that stay," he added.

For now, Robert Yates will spend the night in the Pierce County Jail and most likely be taken right back to death row at Walla Walla after the hearing.

Yates, a blue-collar smelter worker and former Air National Guard helicopter pilot, also faces a 408-year sentence for murdering the 13 other women - all prostitutes he killed in the same manner as the Tacoma women.

Prosecutors said Yates' pattern was to lure prostitutes into his vehicle, pay them for sex and then shoot them in the back of the head, put plastic bags over their heads, rob them and dump their bodies.

Under an agreement, he pleaded guilty to killing 10 women in Spokane County, two in Walla Walla County and one in Skagit County, and was sentenced to 408 years in prison.

Originally, Yates and the Spokane prosecutors thought the two Pierce County slayings would be included in the plea deal. But John Ladenburg, then the Pierce County prosecutor, decided to prosecute him separately for the two Tacoma-area deaths. The jury convicted him and Yates was sentenced to death.