A neighbor arrested in the slayings of an Iraq soldier's family told police he woke up in the victims' home after an alcoholic blackout, covered in blood, according to court records.

While prosecutors said they expect to file murder charges against the neighbor, National Guard Sgt. Leonid Milkin returned to his burned-out home Thursday, still wearing his fatigues. He glanced briefly at a memorial before entering the home with investigators, but spent most of the day with family.

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Investigators had not determined a motive in the slayings of Milkin's wife, two sons and sister-in-law. Each of the victims was stabbed more than once in the neck, police said. The fire gutted the two-story house Monday in this suburb east of Seattle and was fueled with gasoline.

Milkin, assigned to the 415th Military Intelligence Battalion in Baghdad, was granted emergency leave.

"You can only imagine what he could be going through — to come back and find his home burned and his beloved family dead, gone," said Maj. Philip Osterli, a Guard spokesman.

King County Deputy Prosecutor Scott O'Toole said he expects to file four counts of aggravated first-degree murder Monday against the neighbor, Conner M. Schierman, 24.

Schierman was ordered held on $4 million bail following a court appearance Thursday. O'Toole said no decision had been made about whether to seek the death penalty.

"He admits to setting the fire. He admits to leaving the victims' house covered in blood," O'Toole said.

After the fire was extinguished, investigators discovered the charred bodies of Olga Milkin, 28; her sons Justin, 5, and Andrew, 3; and her sister, Lyubov Botvina, 24, who lived at the house.

The county medical examiner determined that three of the four had been stabbed repeatedly in the neck, head and chest, and the youngest suffered a slit throat.

Schierman appeared to have defensive wounds to his arms and face, O'Toole said, when the man was arrested Wednesday for investigation of arson and homicide.

The six-foot, 215-pound Schierman moved in across the street from the Milkins earlier this month.

Schierman had worked the past year and a half doing maintenance for Carillon Properties, an upscale collection of offices, shops, a hotel and a marina on Lake Washington.

"He's always been a good worker," said Carillon general manager Barbara Leland. "He had no problems, no warning signals, nothing. Everybody liked him."