The man accused of killing conservative firebrand Charlie Kirk, Tyler Robinson, is set to appear in court today as prosecutors prepare to outline their case for murder.

Formal charges are expected to be filed and announced on Tuesday morning by Utah County Attorney Jeff Grey in advance of the court hearing where more details are expected to be released. 

Mr. Robinson was arrested last week on suspicion of aggravated murder, felony discharge of a firearm, and obstruction of justice — charges that could carry the death penalty.

Additional federal charges are also expected in the coming days as investigators continue examining evidence, including electronic devices potentially used by the alleged shooter.

The FBI director, Kash Patel, said during an interview with Fox News that Mr. Robinson has not cooperated with authorities since his arrest.

“He has not confessed to authorities. He is not cooperating, but all the people around him were cooperating,” he said on “Fox and Friends.”

Investigators are also looking at a series of messages allegedly posted by Mr. Robinson on the messaging platform Discord just hours before he was arrested.

“Hey guys, I have bad news for you all. It was me at UVU yesterday. im sorry for all of this,” reads the message from an account belonging to Mr. Robinson, which was first reported by the Washington Post.

Three friends reportedly confronted Mr. Robinson on the messaging platform about FBI photos showing the shooter’s resemblance to him, and he didn’t deny it, law enforcement sources said, adding that one friend jokingly told Mr. Robinson to stay away from McDonald’s, referencing where the accused UnitedHealthcare CEO shooter, Luigi Mangione, was nabbed with a manifesto, rifle, and fake ID.

“Whatever you do don’t go to a mcdonalds anytime soon,” the friend wrote.

“Better also get rid of this manifesto and exact copy rifle I have lying around,” Mr. Robinson allegedly wrote in response.

A representative of Discord confirmed to CBS News that messages from Mr. Robinson’s account showed that he was getting ready to turn himself in.

“im surrendering through a sheriff friend in a few moments, thanks for all the good times and laughs, you’ve all been so amazing, thank you all for everything,” one message on his account read.

The FBI is also investigating social media posts made by others in advance of the shooting.

The deleted social media posts weren’t necessarily from Mr. Robinson but appear to show advanced knowledge of the plot, according to the Washington Free Beacon. The posts mentioned Kirk and contained violent fantasies about his death, with some accounts reportedly belonging to transgender individuals.

“Itd be funny if someone like charlie kirk got shot on september 10th LMAO,” one X user posted on September 3.

Another post, dated from August 6, stated that “september 10th will be a very interesting day.” The user responded to the message with “I plead the fifth” after Kirk’s assassination.

Another user posted, “WE F—ING DID IT” after Kirk was killed.