Authorities are continuing to investigate the reasons behind the tragic shooting of Charlie Kirk at a Utah college, as his family organizes a memorial for him next week to honor his life and contributions.

Tyler James Robinson, 22, from Washington, Utah, has been detained on charges of aggravated murder and other serious offenses. Formal charges are being prepared and may be filed early next week ahead of his initial court hearing.

Police have interviewed Robinson’s family members and executed a search warrant at their residence in Washington, located roughly 240 miles (390 kilometers) southwest of Utah Valley University, where the incident occurred.

Here are things to know about the killing:

What do we know about motive?

Authorities have not provided many details about why they think Robinson carried out the attack on Kirk.

Utah Governor Spencer Cox mentioned that Robinson’s family members informed investigators that he had shown increased political interest recently. They recalled a discussion at the dinner table about Kirk’s planned visit to Utah Valley University and debated whether the activist was promoting hateful ideologies.

State records indicate that Robinson is a registered voter with no party affiliation and is considered inactive due to not participating in the last two general elections. His parents are registered as Republicans.

The ammunition found with the gun used in the killing bore provocative, anti-fascist, and meme-related inscriptions. One bullet casing carried the message, “Hey, fascist! Catch!” according to Cox.

What do we know about Robinson?

He grew up around St. George, in the southwestern corner of Utah between Las Vegas and natural landmarks including Bryce Canyon and Zion National Parks.

Robinson became a member of The Church of Jesus Christ of Latter-day Saints, known widely as the Mormon church, at a young age, church spokesperson Doug Andersen said.

Robinson has two younger brothers, and his parents have been married for about 25 years, according to social media posts. Online activity by Robinson’s mother reflects an active family that took vacations to Disneyland, Hawaii, the Caribbean and Alaska.

Like many in that part of Utah, they frequently spent time outdoors — boating, fishing, riding ATVs, zip-lining and target shooting. A 2017 post shows the family visiting a military facility and posing with assault rifles. A young Robinson is seen smiling as he grips the handles of a .50-caliber heavy machine gun.

A high school honor roll student who scored in the 99th percentile nationally on standardized tests, he was admitted to Utah State University in 2021 on a prestigious academic scholarship, according to a video of him reading his acceptance letter that was posted to a family member’s social media account.

But he attended for only one semester, according to a university spokesperson. He is currently enrolled as a third-year student in the electrical apprenticeship program at Dixie Technical College in St. George.

What has the fallout from the assassination been?

It prompted calls for greater civility in the country’s political discourse, especially on social media. But many people have made comments about the Kirk and the shooting that brought consequences, including firings.

MSNBC political analyst Matthew Dowd lost his job shortly after on-air comments about Kirk, one of the first of many figures to experience similar fallout.

Office Depot said Friday that it fired a worker at a Michigan store who was seen on video refusing to print flyers for a Kirk vigil and calling them “propaganda.”

Several Delta Air Lines employees were also suspended after social media posts that “went well beyond healthy, respectful debate,” CEO Ed Bastian said in a message to the company.

Florida Gov. Ron DeSantis’ education commissioner warned teachers in the state that making “disgusting” statements about Kirk’s assassination could draw sanctions, including the suspension or revocation of their teaching licenses.

A conservative internet personality who is embedded with immigration agents in Chicago filmed a video outside Illinois Gov. JB Pritzker’s private home in which he urged viewers to “take action” after Kirk’s assassination. Pritzker’s office said his security has been increased in recent days.

Memorial to be held in Arizona

Turning Point USA, Kirk’s conservative organization, will hold a memorial for him Sept. 21 at State Farm Stadium outside Phoenix, where the Arizona Cardinals play.

Kirk’s casket arrived Thursday in his home state aboard Air Force Two, accompanied by Vice President JD Vance.

His widow, Erika Kirk, vowed to continue his campus tour and his radio and podcast shows.

“To everyone listening tonight across America, the movement my husband built will not die,” she said Friday in a livestreamed video. “It won’t. I refuse to let that happen.”

Flowers, U.S. flags and handwritten messages were left at a makeshift memorial for Kirk at Utah Valley University’s main entrance. The school has said there will be increased security when classes resume Sept. 17.