() An armed man who claimed to be law enforcement was arrested at State Farm Stadium on Friday, according to the U.S. Secret Service.

The arrest came just two days before the memorial service for conservative activist Charlie Kirk is set to take place at the stadium on Sept. 21. A heavy security presence is expected and federal authorities are currently tracking any threats to the service.

The Secret Service told that the man was armed with a knife and a gun and was “acting suspiciously,” and that both Secret Service and local law enforcement is investigating why he was at the location.

Sunday’s service has been given a Level 1 Special Event Assessment Rating (SEAR) by the Department of Homeland Security, a top designation that gives the federal government sweeping powers to enforce security around the venue. This designation is usually given to big events like the presidential inauguration and the Super Bowl.

The man, who has not been identified, has been charged by the Arizona Department of Public Safety.