Bill Thompson, the lead prosecutor on the Idaho murders case, spoke in an interview with NBC News just two days after Bryan Kohberger recieved four consecutive life sentences for killing four University of Idaho students.

Thompson spoke to NBC’s Liz Kreutz in an interview that aired July 25 on TODAY and addressed the fact that, though the case is closed from a legal standpoint, many questions remain about the night of Nov. 13, 2022. One of those outstanding questions: Why did Kohberger kill Madison Mogen, Kaylee Goncalves, Xana Kernodle and Ethan Chapin?

“It would always be nice to have an answer to everything, but the reality is, is that we don’t always have that luxury,” Thompson said of the lack of a motive.

Thompson negotiated Kohberger’s controversial plea deal, in which the 30-year-old pleaded guilty to the charges against him — four counts of first-degree murder and one burglary count — earlier this month to avoid a death penalty sentence.

“One way or another, he’s going to be in prison until he dies,” Thompson said.

On July 23, Kohberger was sentenced to life in prison without the possibility of parole for the murders of Mogen, Goncalves, Kernodle and Chapin, three weeks after he pleaded guilty to the charges on July 2.

Before Kohberger was sentenced, family and friends of the victims read impact statements in the courtroom, including Bethany Funke and Dylan Mortensen, the two roommates who were home at the time of the attack and survived.

Funke had her statement read by a friend, while Mortensen emotionally read hers sitting beside Thompson, instead of speaking at a podium.

“I had been asked to block his view of her so she made her statements at the court,” Thompson said. “That was something I’ve never experienced before, watching the strength of that young lady, describing not only what happened that night, but what her life has been, the hell her life has been since then.”

Thompson said Mortensen didn’t speak at the podium so that she wouldn’t have to see Kohberger, and that he couldn’t see her.

He added that it is unclear why Kohberger left after passed by Mortensen on the night of the murders.

“I’m sure there are theories,” he said. “Dylan had an angel watching over her.”

Judge Steven Hippler, the judge presiding over the case, also addressed the lack of answers before he sentenced Kohberger.

“I share the desire expressed by others to understand the ‘why,’” Hippler said. “But upon reflection, it seems to me, and this is just my own opinion, that by continuing to focus on why, we continue to give Mr. Kohberger relevance. We give him agency and we give him power.”

Kohberger did not address the court after all of the statements had been read, telling Hippler he “respectfully” declined to speak.

Hippler expressed concern about Kohberger eventually speaking out about the murders, whether in a book, documentary or other media project, but Thompson said he didn’t care.

“I don’t care if he writes book. I say that not to be cavalier, because I will feel for the families if he tries to make to write a book and profit off of it,” Thompson said. “And there are laws in Idaho that we can use to help control that, and we’ve already had these discussions with the families. My preference is that he just disappear into the Idaho Department of Corrections, like I said yesterday, close the door forever. He will get out of their custody when he dies.”

Hours after the sentencing hearing, Kohberger was transferred to Idaho’s maximum security prison, where he started serving his sentence.