Joe Walsh is a senior editor for digital politics at CBS News. Joe previously covered breaking news for Forbes and local news in Boston.

A memorial service for conservative activist Charlie Kirk in Arizona on Sunday is set to feature President Trump, Kirk's widow, Erika Kirk, and more than half a dozen top Trump administration figures addressing what could be an NFL-size crowd at State Farm Stadium.

Kirk, the 31-year-old co-founder of Turning Point USA, was shot and killed as he spoke at an event at Utah Valley University on Sept. 10. A 22-year-old suspect has been charged with aggravated murder.

Kirk's assassination has rocked the conservative world. A prolific and sometimes controversial speaker, Kirk was known for his college campus events and debates, his role in mobilizing GOP voters and his close ties to the Trump administration.

Where is Charlie Kirk's memorial service taking place?

The service will take place at State Farm Stadium in Glendale, near Phoenix. The stadium, which is home to the NFL's Arizona Cardinals, can typically seat up to 63,400 people.

Organizers say security will be tight, with "TSA-level screening" expected.

Federal authorities have designated the memorial service as a Special Event Assessment Rating (SEAR) Level 1 event, a senior Department of Homeland Security official said. That designation is used for "significant events with national and/or international importance that require extensive federal interagency support," like the Super Bowl.

What time is Charlie Kirk's memorial service?

The service is scheduled to start at 11 a.m. local time in Arizona, or 2 p.m. ET.

Who will speak at Charlie Kirk's memorial service?

President Trump and Vice President JD Vance are both scheduled to speak, along with the activist's widow, Erika Kirk, who was named Turning Point USA's new CEO on Thursday.

Several other administration officials are set to speak, including White House Chief of Staff Susie Wiles, Secretary of Health and Human Services Robert F. Kennedy Jr., Secretary of Defense Pete Hegseth, and key Trump aides Stephen Miller and Sergio Gor.

The president's eldest son, Donald Trump Jr., is also listed as a speaker, as is right-wing media personality and former Fox News host Tucker Carlson.

Many of the speakers had extensive personal and professional ties with the slain activist.

Kirk was a stalwart supporter of the president starting during his first campaign in 2016, and he remained allied with Mr. Trump after he left office under a cloud of controversy following the Capitol riot in January 2021. In last year's presidential race, Kirk's Turning Point USA was widely credited with assisting the Trump campaign with grassroots voter mobilization.

Kirk was also close with Donald Trump Jr., and worked closely with the younger Trump as an aide during the 2016 campaign. "Charlie wasn't just a friend -- he was like a little brother to me," Donald Trump Jr. wrote on X.

Vance has credited Kirk with introducing him to Donald Trump Jr. ahead of his 2022 Senate campaign, and with advocating "in public and private" for the president to choose Vance as his running mate last year. Kirk's body was flown from Utah to Arizona on Vance's jet, Air Force Two.

Kennedy has called Kirk the "primary architect of my unification with President Trump," referring to the former Democrat's decision to drop his independent campaign for president last year and publicly endorse Mr. Trump at a Turning Point Action rally.

Several Christian musicians are also listed on the program: Chris Tomlin, Brandon Lake, Phil Wickham, Kari Jobe Carnes and Cody Carnes.

Who was Charlie Kirk?

Kirk was the leader of Turning Point USA, a group for young conservatives that he co-founded in 2012, at the age of 18. A native of the Chicago area, Kirk briefly attended community college but dropped out to pursue political activism full-time.

He was a ubiquitous presence in politics: He hosted a daily talk radio show and podcast, and he visited scores of college campuses every year, where he was known for hosting rapid-fire debates with left-leaning students.

Kirk frequently drew controversy for his views. He supported Mr. Trump's false claims of voter fraud after the 2020 election, and his group maintained a "Professor Watchlist" of college instructors accused of spreading "leftist propaganda."

Turning Point USA says it has chapters at thousands of high schools and colleges, and the group's political arm, Turning Point Action, engages in grassroots canvassing.

Kirk was also a family man with two young children

"He was the perfect father. He was the perfect husband," Erika Kirk said last week in her first public remarks after the shooting.

Who is Erika Kirk?

Charlie and Erika Kirk wed in 2021, after they began dating in 2018.

A Phoenix-area native, Erika Kirk won Miss Arizona USA in 2012, attended Arizona State University and later earned a juris master degree from Liberty University.

She was a frequent presence at Turning Point USA events, where she spoke about politics, religion and her conservative views on family and marriage. She also founded a clothing line called PROCLAIM and a ministry called BIBLEin365.

During one appearance on "The Charlie Kirk Show" earlier this year, Erika Kirk said she's more conservative than her husband.

"Not even close," her husband agreed. "I am a moderate compared to Erika."

In public remarks two days after Charlie Kirk's assassination, Erika Kirk vowed that the "movement my husband built will not die."

On Thursday, the board of Turning Point USA announced it had unanimously chosen Erika Kirk to serve as the organization's new chair and CEO.

How to watch Charlie Kirk's memorial service

The memorial service will be livestreamed midday on Sunday.

* What: Public memorial service for Charlie Kirk

* Date: Sunday, Sept. 21, 2025

* Time: 11 a.m. local time; 2 p.m. ET

* Location: State Farm Stadium in Glendale, Arizona

* Online stream: Live on CBS News 24/7 on your mobile or streaming device

Note: Streaming plans are subject to change.

Nicole Sganga contributed to this report.

Charlie Kirk memorial service to honor the conservative activist Sunday. Here's how to watch and more details.