The Island County Prosecutor’s Office charged 61-year-old Greenbank resident Robert “Al” Baker Wednesday with first-degree murder, a domestic-violence crime with a deadly weapon enhancement and an aggravating factor.

Baker, who turns 62 Thursday, is being held in Island County jail on $5 million after a judge found probable cause to hold him for the murder of his wife, 53-year-old Kathie Baker.

A detective’s report on the case indicates that the motive for the murder may have been another woman. A woman from Alaska was staying with Al Baker at his Greenbank home while Kathie’s tarp-wrapped body was in a ravine at the back of the house, court documents state.

Kathie was last seen alive June 2. Deputies with the Island County Sheriff’s Office started investigating her disappearance after Kathie’s boss at Raytheon Corporation in Denver reported that he couldn’t get hold of her.

After finding bloody drag marks in the house and getting contradictory stories from Al Baker about his wife’s whereabouts, detectives obtained a search warrant for the home and called in the state patrol’s Crime Scene Response Team to help process the scene, according to court documents.

Kathie’s body was found June 9. The cause of death was determined to be blunt force trauma to the head and ligature strangulation. Investigators found a ball-peen hammer with hair stuck to it in a trash can in the garage.

The Bakers owned Harbor Pizzeria in Freeland.

Chief Criminal Deputy Eric Ohme, who’s handling the case, said the Bakers were married in 2007 and aren’t believed to have any children. They both worked as research scientists in Antarctica.

If convicted, Baker could face up to 28 years in prison under the standard sentencing range and including a two-year deadly weapon enhancement. In addition, the aggravating factor could add to the sentence if a jury finds that the victim was “particularly vulnerable or incapable of resistance.”