Tyler Robinson, suspected of assassinating Charlie Kirk, was afraid of being shot by police before he negotiated a peaceful surrender, police said.

More details have emerged about how alleged Charlie Kirk assassin Tyler Robinson was turned over to police while the manhunt for a suspect ensued. 

Washington County Sheriff Nate Brooksby said at a news conference Wednesday he received a call from a former law enforcement friend telling him Robinson, 22, was the shooter. Robinson reportedly had suicidal thoughts but was convinced by his parents not to harm himself. 

Brooksby said Robinson knew  he would be caught and was afraid of a SWAT raid on his home. He was also afraid of being shot by the police, the sheriff said.

TIMELINE OF CHARLIE KIRK ASSASSINATION 

"Tyler knew it was just inevitable with all the law enforcement pressure that he, his picture in the news, the gun, the gun on the news," he said. "He knew it was inevitable that he would be caught."

According to Brooksby, the call from his friend came in at 8:02 p.m. Thursday. 

"I could tell his voice was kind of shaky, so my first thought is, ‘Who died?’" he said. "'Like, who's he gonna tell me that died?' And then I couldn't fathom what actually came out of his mouth.

"So he said, ‘Hey, I know who Charlie Kirk’s shooter is. I know the family through religious association, and he's in Washington County now. And we're working to get him to come in voluntarily,'" Brooksby continued. 

"During that phone call, some information was provided about Tyler potentially having some suicidal ideation [and] was en route to a remote part of Washington County. The parents convinced him not to do that and conveyed that they would stand by him and help him surrender peacefully."

Robinson asked for a "peaceful, gentle" surrender, a condition to which the sheriff agreed to in order to get him to turn himself in. He was described as "quiet and somber" upon apprehension. 

Brooksby's office did not question Robinson while he waited for the lead investigators to arrive. 

Speaking about Robinson's family and his roommate and lover, Lance Twiggs, the sheriff said, "They need to lay low for a long time" but did not elaborate further. 

Brooksby told Fox News earlier in the day that Twiggs is in a "safe space very far away from St. George," the Utah town where the pair lived. He added that law enforcement officials from outside of his agency are talking to Twiggs' associates. 

According to Brooksby, there is a Washington County Sheriff's deputy with the last name Robinson who is not related to the shooter as was initially rumored. He asked the media to make that point clear because the unrelated Robinson continues to be harassed. 

Robinson's lover, who is transgender, lived in a townhouse with him for about a year, according to a relative who spoke to Fox News Digital. 

"He hates conservatives and Christians," the relative said. "He hated us. He was not raised that way, but he, over the years, has become really detached [and] been radicalized."

COMPLETE COVERAGE OF CHARLIE KIRK 

"He has obviously gotten progressively worse the last year or two," the relative said, adding that he's "always very angry."

Robinson faces charges of aggravated murder, two counts of obstruction of justice and felony discharge of a firearm causing serious bodily injury, two counts of witness tampering and commission of a violent offense in the presence of a child.

Kirk was hosting the first event in his The American Comeback tour last Wednesday when he was shot and killed.

Authorities say Robinson climbed onto the roof of the Losee Center at Utah Valley University in Orem, Utah, and discharged one round from a rifle, striking Kirk in the neck. 

Kirk, a conservative titan who traveled the country fostering debate and open dialogue with university students, was pronounced dead a short while later. 

Fox News' Adam Sabes and Matt Finn contributed to this report.