The stabbing victims' 17-year-old daughter was one of three people in custody Saturday in the investigation of a small-town attack that killed a man and seriously injured his wife, police said.

Two intruders in Halloween masks climbed through a bedroom window about midnight Thursday and attacked Paul and Mara Skinner as they lay in bed. The couple's disapproval of a relationship between their daughter and a male "may have been a factor" in the attack, said detective Pat Young of the Michigan State Police.

No charges have been filed in the stabbings. The couple's adopted daughter remained in jail along with two males, ages 18 and 19, Yale Police Chief Michael Redman said.

Meanwhile, an autopsy confirmed Paul Skinner, 47, died of multiple stab wounds.

"There was nothing that we didn't expect," Young said of the autopsy.

Mara Skinner, a 44-year-old teacher, was recovering from her injuries at a hospital. She had more than 20 knife wounds.

"This was not a spur-of-the-moment, random act," Young said. "This was a planned event which involved several days."

The Skinners' daughter and a son in his 20s were inside the house when the attack happened. The son was visiting from the Grand Rapids area in western Michigan, said Young, who declined to release his name.

"We're very comfortable he's not involved," the detective said. "He ran for help. He went to a neighbor's house and physically attempted to help his father."

Yale is about 85 miles northeast of Detroit in Michigan's Thumb region.