Bryan Kohberger had identified a single target on the night he allegedly murdered four college students in Idaho, a new book has claimed.

Murder suspect Kohberger was fixated on Madison Mogen when he entered the off-campus house in Moscow on November 13, 2022, according to journalist Howard Blum.

The 29-year-old criminology PhD student is currently awaiting trial for the murders of Mogen, Kaylee Goncalves, Xana Kernodle, and Ethan Chapin, who were all found stabbed to death.

Officials believe Kohberger was after Mogen because he passed the rooms of two surviving roommates before starting the killing spree, Blum told ABC News.

“If he was just on a killing spree, it would have been natural, instinctive, to go to one of those doors,” he said. “Instead he goes up this narrow staircase and he turns directly into Maddie’s room, and I think Maddie was his target.”

Police linked Kohberger to the murders that rocked the college town through DNA found on a knife sheath, cell phone data, an eyewitness account and his white Hyundai Elantra.

Blum’s book also claims that Kohberger’s family had concerns about his behavior leading up to his arrest six weeks after the murder. His father said he had been “on edge” when he picked him up from school after the killings.

“[Kohberger’s father] has been reading the headlines – he knows that four students were killed 12 miles from his son’s house. He knows what a troubled son he has,” Blum told ABC.

One of Kohberger’s two sisters had also approached their father to voice suspicions about him, but he had brushed off the concerns, unwilling to “confront” the possibility.

Blums’ book, When the Night Comes Calling: A Requiem for the Idaho Student Murders is set to be released on June 25.

It comes after a hearing in the case was set for June 27 where attorneys are expected to discuss dates for the trial and sentencing.

They will also discuss whether the trial should be moved outside the county to seat an impartial jury. The state has been opposed to the move, while the defense is in favor of it.

Kohberger previously declined to enter a plea prompting Judge John Judge to enter his plea as not guilty on his behalf in May 2023. Latah County prosecutors say they intend to seek the death penalty if Kohberger is convicted.

Last month, the defense argued that prosecutors had not handed all the evidence over for them to review and have filed multiple motions to compel the state to do so.

Prosecutors insisted they are doing all they can to share evidence but have been partly delayed by federal rules, due to the FBI’s involvement in the investigation.

Earlier this year, Kohberger’s attorneys also filed a motion to dismiss the murder charges against him, citing a biased grand jury, inadmissible evidence and prosecutorial misconduct. Judge Judge denied the motion.