A surviving roommate of the University of Idaho murder victims allegedly thought the noises she heard that night were more partying.

This new narrative of the night Xana Kernodle, Ethan Chapin, Kaylee Goncalves, and Madison Mogen were murdered comes from an anonymous source who spoke exclusively with NewsNation. But the narrative matches the narrative that same roommate gave to police in only one point: She said she saw the man believed to be the killer as he left the house after the murders.

The unnamed source, who said they spoke with roommate Dylan Mortensen, told NewsNation Mortensen said she yelled about all the noise she thought was just loud merriment — something that wasn’t at all uncommon at what’s become known as the murder house.

“Calm down, you’re being loud!” the source quoted Mortensen as saying at about 4 a.m. when she briefly opened her second floor bedroom door. “I’m trying to sleep!”

The unidentified source told NewsNation that Mortensen closed the door and locked it, but minutes later, opened it again and saw a man she assumed was a guest of the other roommates as he walked down the hall and left the house through a second floor door.

Investigators believe the man she saw was suspect Bryan Kohberger.

Mortensen allegedly told the unnamed source she wasn’t frightened when she saw the man, but she told police “she stood in a ‘frozen shock phase'” as he walked past her and out the sliding glass door, according to Kohberger’s arrest affidavit.

In the affidavit, Mortensen told investigators she was awakened at about 4 a.m. by what she thought was Kaylee “Goncalves playing with her dog in one of the upstairs bedrooms.” A short time later, the affidavit says, Mortensen thought she heard Goncalves say something like “there’s someone here,” but investigators said that could have been Xana Kernodle’s phone — records show she was accessing TikTok at about 4:12 a.m., after she received a DoorDash order at about 4 a.m.

Mortensen told investigators that she looked out her door after the comment about someone being there, but saw nothing. Then, she said, she “opened her door a second time when she heard what she thought was crying coming from Kernodle’s room,” which was also on the second floor.

“D.M. then said she heard a male voice say something to the effect of ‘it’s ok, I’m going to help you.”

Mortensen told police she opened her door a third time, and that’s when she “saw a figure clad in black clothing and a mask that covered the person’s mouth and nose walking towards her.”

She described him as “not very muscular, but athletically built with bushy eyebrows” and said she locked herself in her room after he left.

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[Featured image: Left, Ethan Chapin and Xana Kernodle; Top right: Kaylee Goncalves; Bottom right: Madison Mogen/Instagram]