PROVO, Utah (AP) — A former campus police officer testified Monday that he found an apparent “sniper pad” on a rooftop near where Charlie Kirk was assassinated, as prosecutors sought to convince a state judge they have enough evidence to put a Utah man on trial for murder.

Former Utah Valley University Officer Christopher Bagley said he witnessed Kirk’s shooting as the conservative activist spoke to a crowd of thousands last year. Soon after, he went to a nearby gravel rooftop, where it appeared someone had been lying prone with a clear sightline to Kirk’s location, Bagley said.

“It looks like a sniper pad,” Bagley said, adding, “you’ve got markings of elbows, knees and feet.”

The testimony came as Kirk’s parents, Kathryn and Robert, and widow, Erika, were in the courtroom for the first time since the case began, along with Donald Trump Jr., President Donald Trump’s son.

Prosecutors are seeking the death penalty for defendant Tyler Robinson. A five-day preliminary hearing that began Monday marks the most significant presentation of evidence to date in the case.

Robinson’s parents also were present, sitting a few rows behind the Kirks as the hearing began. The 23-year-old defendant is charged with aggravated murder in the Sept. 10 assassination of Kirk, a conservative activist and ally of President Donald Trump, at Utah Valley University. Robinson turned himself in the day after the shooting.

Prosecutors allege he confessed in a note left for his roommate, who was also his romantic partner, that read: “I had the opportunity to take out Charlie Kirk and I’m going to take it.”

Robinson has not yet entered a plea, and his attorneys have not commented on his guilt or innocence. They have, however, sought to get the death penalty taken off the table, so far unsuccessfully.

Robinson sat quietly between his attorneys on Monday, looking at the prosecution’s exhibits on a monitor and occasionally taking notes. He wore a gray suit, and his wrists were shackled to a chain around his waist.

Charlie Kirk’s parents and widow walked out of the courtroom when a police officer started testifying about Kirk’s arrival on campus the day he was shot. They later returned.

The proceeding resembles a minitrial, but prosecutors need only demonstrate that there are reasonable grounds to believe Robinson killed Kirk. The standard is lower than for a trial, where prosecutors must prove guilt “beyond a reasonable doubt.”

Prosecutors as a result should have little trouble advancing their case, said Mark Kouris, a former prosecutor and state judge in Salt Lake City.

“This standard is extremely low and the chances of them not getting through it are, quite frankly, almost nothing,” said Kouris, now an adjunct professor at the University of Utah’s S.J. Quinney College of Law. ”

Bagley, the prosecution’s first witness, said he could see the right side of Charlie Kirk’s body as Kirk spoke on campus. Kirk was answering a question when Bagley heard a gunshot.

“I saw him go to the left … I could no longer see the right side of his body,” Bagley said. “Then everybody started getting up and started to run, more of a chaos situation.”