An armed man posing as law enforcement was detained at an Arizona stadium where a memorial service for Charlie Kirk is set to take place on Sunday, the Secret Service said.

The man entered State Farm Stadium in Glendale, Arizona, on Friday and was “exhibiting suspicious” behavior, a Secret Service spokesperson said in a statement Saturday. The spokesperson added that the man, whose name the agency did not reveal, was posing as law enforcement and was armed.

“The individual is not a member of authorized law enforcement working the event and is currently in custody,” the spokesperson said. “The U.S. Secret Service and local law enforcement are investigating the circumstances as to why he was at the location.”

The memorial service for Kirk is expected to draw a massive audience, which will include President Donald Trump, Vice President JD Vance and other elected officials.

Kirk, a conservative activist with a popular podcast, “The Charlie Kirk Show,” was assassinated this month while speaking at an event at a college campus in Utah. He was 31 years old and left behind a wife and two children.

His murder followed a series of political acts of violence in the United States in the last year, including the assassinations of former Minnesota House Speaker Melissa Hortman and her husband, Mark, in their home, and an arson at the home of Pennsylvania Gov. Mark Shapiro. Trump also faced two assassination attempts while campaigning for the presidency last year.

Kirk’s assassination has done little to quell charged political rhetoric that has gripped the nation for the better part of a decade.

Social media has arguably become even more of a cesspool of hate since the Sept. 10 attack, with extremists flooding news feeds celebrating Kirk’s killing and others calling for civil war.