A brutal knife attack that left a man dead and his wife seriously wounded may have been planned a week in advance, and the couple's demand that their adopted daughter break up with her boyfriend was the likely motive, police said Monday.

Investigators were focusing on the relationship between Tia Marie-Mitchell Skinner, 17, and Jonathan Kurtz, 18 — both now charged in the stabbings — as the reason for the Friday morning attack, Michigan State Police Detective Sgt. Pat Young told The Associated Press.

"This was not a spur-of-the-moment act," Young said. "It was planned, possibly, up to a week in advance. We believe if Tia didn't want this to happen, it would not have happened."

Skinner, Kurtz and his 18-year-old neighbor, James Preston, were arraigned over the weekend on murder, attempted murder and conspiracy charges. They were being held without bond in the St. Clair County Jail pending a Nov. 23 hearing.

Paul Skinner, 47, and Mara Skinner, 44, were attacked after two men, wearing masks or bandanas, broke in through a window of their home and attacked the couple while they were in bed, Yale Police Chief Michael Redman said.

Mara Skinner is recovering from more than 20 knife wounds. Her husband died in the house.

The couple recently told their adopted daughter, who is also their niece, that she could no longer have any contact with Kurtz, Redman said.

Police said she was in the basement living area of the couple's house, where she also lives, when the attack took place. Redman said the brother, who did not live there, heard the commotion and ran to his parents' aid only after his father had fought off their assailants, driving them out the front door.

Police do not believe the couple's son was involved in the attack.

"We're trying to tie evidence together with blood and fingerprints," he said.

Two bloody knives were found in the house after officers arrived, Redman said. The knives resemble the type used in kitchens, said Young, who added that Tia Skinner, Kurtz and Preston each confirmed they played a role in the attack but made incriminating statements about each other during interviews.

Kurtz and Preston live on the same road in a mix of woods and farms about six miles outside Yale.

They were arrested Friday at or near their homes after police questioned Tia Skinner.

Police spent hours Friday searching both houses. A three-foot pit also was dug at a third house across the road from Kurtz' home.

On Monday outside the Skinner's home, located about a block from Main Street, several flower bouquets were placed at the end of the driveway and steps from the yellow police tape that still stretched around the front of the home.

A plywood board covered the front door.

A sign posted Monday outside the Yale Methodist Church read, "Pray for Our Community," a reference to the tragedy.

Three days after the violent episode, residents of this close-knit village of about 2,000 people were still searching for answers.

"This town is in a real sad state right now. It's like it's at a standstill," said Lisa King, who lives a block or so from the Skinner's home.

First, there was the shock of the initial attack in Yale, a private community around 85 miles northeast of Detroit surrounded by woods and cornfields. But then it was amplified when police announced charges.

"When something bad happens it spreads like wildfire," King said Monday. "Everybody wants to jump in and do what they can do to help somebody."

Many gathered for a weekend meeting that resembled more of a memorial service for the Skinner family.

"Everybody is extremely sad," said Jim Smith, owner of Yale Hardware. "The Skinners are wonderful people. The Preston family is a strong, old family in the community."

Despite the charges against Preston and Kurtz, Smith doubts there will be any divisiveness in Yale or animosity toward the families of the two men.

"You just don't expect things like this to happen anywhere," he said. "We can't second guess the Lord. He allows things to happen and then he heals."