Explosive new book claims to reveal target of Idaho murders and how suspect Bryan Kohberger's family grew suspicious of him BEFORE his arrest

An explosive new book claims Bryan Kohberger had a single target the night he allegedly murdered four Idaho college students - and that his family had suspected him before his arrest. 

Kohberger, 29, was not on a random killing spree, but intended to target only Madison Mogen when he entered the Moscow house in November, 2022, according to journalist Howard Blum's upcoming book - When the Night Comes Calling: A Requiem for the Idaho Student Murders.

Blum told ABC News that officials believe Kohberger was after Mogen because he passed the rooms of two surviving roommates before starting the killing spree that shocked the nation. 

'If he was just on a killing spree, it would have been natural, instinctive, to go to one of those doors,' Blum said. 

'Instead he goes up this narrow staircase and he turns directly into Maddie's room, and I think Maddie was his target.'

Blum also writes of Kohberger's family members being concerned about his behavior leading up to his arrest.

Kohberger's father Michael was reportedly 'on edge' when he picked the alleged killer up from school after the murders.

'[Michael] 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 said.

Blum claims one of Kohberger's own two sisters approached Michael to voice suspicions about her brother but the father ignored her.

'He can't confront it,' Blum told ABC News about the father's reaction at the time.

Meanwhile sources told both Blum and ABC News that the two surviving roommates, Dylan Mortensen and Bethany Funke, were using their cellphones to communicate during and after the murders. 

When the Night Comes Calling: A Requiem for the Idaho Student Murders will be released on June 25. 

As DailyMail.com previously reported, Mortensen, 21, allegedly called out to her friends and roommates during the early morning hours of November 13 to quiet down.

'Calm down, you're being loud!' she reportedly yelled around 4am, in addition to 'I'm trying to sleep!'

The college student then closed and locked her door. 

After hearing some more loud noises that night, Mortensen opened her door again and saw Kohberger  but believed him to be a partygoer. 

Mortensen told law enforcement she had seen a strange figure dressed in black walking past her toward the back exit of the house just after 4am on the night of the murders.

Authorities determined the four students were killed sometime between 4 and 4.25am. Police would not be called to the off-campus residence for another eight hours.

In December, 2022, Kohberger was arrested in Pennsylvania at his parents' house and charged with the murders of Kaylee Goncalves, 21, Mogen, 21, Xana Kernodle, 20, and Ethan Chapin, 20.

Both Mortensen and 21-year-old Bethany Funke were home at the time of the killings, but were left unharmed by the murderer.

Speculators of the shocking case wondered why the surviving roommates went eight hours between the time of the murders and when they called police.

A judge entered a not guilty plea on Kohberger’s behalf in a May 2023 hearing, and for the past several months Kohberger’s defense attorneys and Latah County prosecutors have been wrangling over the evidence and other data gathered throughout the investigation.

So far, 2nd District Judge John Judge has not set a trial date, noting that the case is particularly complicated in part because prosecutors have said they will seek the death penalty if there is a conviction.

But that could change later this month. Judge scheduled a June 27 hearing to discuss the schedule for the rest of the case, including dates for the trial as well as for a possible sentencing.

Earlier this month Judge said investigators working for Kohberger’s defense team would be added to a list of attorneys and defense experts who are allowed to review sealed DNA records that law enforcement used to narrow the the pool of potential suspects. 

The DNA was used for investigative genetic genealogy, in which material found at a crime scene is run through public genealogical databases to find a suspect or a suspect’s relatives. 

Kohberger’s attorneys are also asking for a change of venue. The judge has yet to rule on that request.