Two roommates who were in the house when four of their friends were fatally stabbed near the University of Idaho in 2022 shared their accounts publicly for the first time on Wednesday, describing feelings of loss, guilt and terror.

Dylan Mortensen, one of the surviving roommates, spoke through tears and sharp breaths at the sentencing hearing for Bryan Kohberger, 30, who admitted to the murders this month as part of a plea deal that spared him from the death penalty. He is expected to be sentenced to life in prison later on Wednesday.

Ms. Mortensen described having to sleep in her mother’s bed following the murders, afraid to even close her eyes.

“If I blinked, someone might be there,” she said.

One of the enduring mysteries of the November 2022 killings has been why neither Ms. Mortensen nor the other surviving roommate, Bethany Funke, called 911 for more than seven hours after the attacks. Ms. Mortensen told investigators that she had seen a masked man moving through the house in the middle of the night but retreated back to her room. She texted her roommates and, when there was no response, hunkered down in Ms. Funke’s room until about noon, when friends came to the house and discovered the body of one of the victims.

In court on Wednesday, Ms. Mortensen did not talk about what she witnessed that night. But Ms. Funke, who wrote a statement that was read in court by a friend, described feeling guilt over not doing more, saying she had been unaware of what had taken place upstairs.

“If I had known, I, of course, would have called 911 right away,” Ms. Funke said in her statement. “I still carry so much regret and guilt for not knowing what had happened and not calling right away, even though I understand it wouldn’t have changed anything, not even if the paramedics had been right outside the door.”