An armed man was detained at State Farm Stadium in Arizona, which is where the Charlie Kirk memorial is set to take place on Sunday, according to the Secret Service.

The agency said the man was detained on Saturday following reports about a person who was behaving suspiciously.

The U.S. Secret Service in coordination with local law enforcement in Glendale, Arizona, is investigating an individual who was observed exhibiting suspicious behavior at State Farm Stadium,” the agency said in an email to The National News Desk.The individual was approached by Secret Service and stated during the encounter that he was a member of law enforcement and that he was armed. The individual is not a member of authorized law enforcement working the event and is currently in custody. The U.S. Secret Service and local law enforcement are investigating the circumstances as to why he was at the location,” according to the email.

In a social media post, the Glendale Police Department said authorities are “committed to ensuring a secure environment” ahead and during the memorial. Police urged people who plan to attend to “respect one another, be patient, & create a safe atmosphere.”

President Donald Trump and Vice President JD Vance are set to attend the memorial.

According to ABC News, federal law enforcement agencies said they are “tracking several threats of unknown credibility” against people planning to attend the event, including Trump, Vance, as well as member of Kirk’s family.

“Violent extremists and unaffiliated lone offenders may view the memorial service or related events as attractive attack targets due to the attendance of these individuals, other senior US government officials, state and local government officials, and political activists and due to major international media attention,” ABC News reported, citing a memo that was issued by agencies such as the FBI, Department of Homeland Security, the Secret Service, as well as the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Kirk, 31, was shot and killed while speaking at an event at Utah Valley University on September 10. Kirk was the CEO and co-founder of Turning Point USA.

The suspect was identified as 22-year-old Tyler Robinson and later charged with aggravated murder. The Utah County Attorney’s office said it will seek the death penalty.