(NewsNation) — A survivor of the University of Idaho killings allegedly thought the noise resulted from partying, asked the victims to quiet down and mistook the killer as a guest, a source exclusively told NewsNation.

The source spoke directly with surviving roommate Dylan Mortensen, who allegedly yelled about the noises heard during the killings because she mistook it for partying.

Mortensen allegedly first heard noises around 4 a.m. She opened her door and yelled “calm down, you’re being loud!” and “I’m trying to sleep!”

She then closed her door and locked it, according to the source.

Later in the night, Mortensen heard more loud noises, so she opened her door. She saw the killer walking down the hall, but she wasn’t frightened. She assumed he was a guest of the other roommates there partying, according to the source.

These new details slightly contradict initial reports. In the affidavit released in January, police said a roommate heard noises inside the house and opened her door to find a man “clad in black clothing and a mask” with bushy eyebrows. As the witness stood in a “frozen shock phase,” the man walked toward the back sliding glass door, and she locked herself in her room. She said she did not recognize him, according to the affidavit.

Several internet sleuths asked why the surviving roommate didn’t alert police right away.

Additional details released last week shed light on how the killings unfolded.

Kaylee Goncalves and Madison Mogen were killed first, and sources confirmed to NewsNation that Ethan Chapin and Xana Kernodle were killed on the second floor afterward.

They also said that Chapin was killed in the doorway of Kernodle’s room, and Kernodle apparently fought back. She repeatedly grabbed the knife from suspect Bryan Kohberger, and she suffered deep cuts to her fingers. Chapin apparently suffered a slash to the neck, according to sources.

In December, Bethany Funke, the other surviving roommate, and Mortensen wrote heartfelt statements about their friends, which a youth pastor read publicly and shared with the world.

Mortensen wrote, “I know somewhere Xana and Ethan are together, keeping each other company, watching us and telling us, ‘It’s OK’ and that ‘we have each other.’ Maddie and Kaylee, the inseparable duo, the two best friends that were like sisters.”

Funke said she wishes she could give each of her roommates “one last hug” and be able to tell them she “loved them.”

“You always told me that everything happens for a reason,” Funke wrote. “But I’m having a really hard time trying to understand the reason for this.”