A six-hour standoff has ended after a man armed with an AR-15 rifle threatened officials at an FBI building in Cincinnati and was killed in a shootout with police.

The incident began Thursday morning when the suspect who has been identified by multiple publications as 42-year-old Ricky Shiffer attempted to enter the FBI building before he fired a nail gun at the building and fled in his car. The man was also armed with an AR-15.

At approximately 9 AM this morning an armed subject attempted to breach the Visitor Screening Facility at #FBI Cincinnati, the FBIs Cincinnati bureau said on Twitter . After an alarm and a response by FBI special agents, the subject fled north onto Interstate 71.

Police later exchanged gunfire with the suspect after he pulled over in a standoff that lasted most of the afternoon.

In a social media post in May, Shiffer replied to a photograph of rioters scaling the walls of the Capitol during the Jan. 6, 2021, attack. In his message, Shiffer claimed he had been at the building and blamed the attack on outside forces, The New York Times reported .

Clinton County, Ohios Emergency Management Agency announced Thursday afternoon that the law enforcement response and operations has ended after a six-hour standoff.

The FBI has faced increased threats over the past couple days following the execution of a search warrant at Mar-a-Lago, the Florida home of former President Donald Trump . The search appeared to be related to classified material Trump brought with him after he left the White House.