Authorities are investigating the motives of a gunman who tried to break into an FBI office in Cincinnati and was killed in a shootout — an outburst of violence that unfolded amid FBI warnings that federal agents could face attacks in the wake of the home investigation of Donald Trump. Federal authorities are looking into whether the gunman, 42-year-old Ricky Schiefer, had ties to far-right extremist groups such as the Proud Boys, according to a law enforcement official briefed on the matter. Schieffer is believed to have been in Washington in the days leading up to the Jan. 6, 2021, riot and may have been on Capitol Hill that day, according to the official, who was not authorized to discuss the investigation publicly and spoke on condition of anonymity. Schieffer has not been charged with crimes in connection with the Jan. 6 attack, the official said. Officials have warned of an increase in threats against federal agents following Monday’s FBI search of Trump’s Florida estate, Mar-a-Lago. Supporters of the former president have protested the investigation, accusing the FBI and Justice Department of using the legal system as a political weapon. In the Cincinnati case, officials said Schieffer tried to breach the visitor control area at the FBI office Thursday and fled when agents confronted him. He was later spotted by a state trooper along Interstate 71 and fired as the officer chased him, said Lt. Nathan Dennis, a spokesman for the Ohio State Patrol. Schiffer eventually got out of his car on a rural road and exchanged gunfire with police and was wounded, Dennis said. Authorities tried to negotiate with him, but he was shot and killed after he raised a gun at officers, Dennis said. Schieffer was a registered Republican who voted in the 2020 primary from Columbus, Ohio, and in the 2020 general election from Tulsa, Oklahoma, according to public records. Court records show the Ohio Department of Taxation filed a lawsuit against him in June, seeking a $553 tax judgment, according to court records that list him at an address in St. Petersburg, Florida. He also previously lived at several addresses in Columbus. Since the Mar-a-Lago investigation, users of Gab, a social media site popular with white supremacists and anti-Semites, have warned that they are preparing for armed revolution. Federal officials are also monitoring threats of violence against federal agents on Gab and other sites. FBI Director Christopher Wray denounced the threats as he visited another FBI office in Omaha, Nebraska, on Wednesday. “Violence against law enforcement is not the answer, no matter who you’re upset with,” he said. The FBI also warned its agents on Wednesday to avoid protesters and ensure their security key cards “are not visible outside of FBI premises,” citing an increase in social media threats against office staff and offices. —— Welsh-Huggins reported from Columbus, Ohio. Associated Press writers Samantha Hendrickson and Julie Carr Smyth in Columbus, Michael Balsamo in Washington and Jim Mustian in New York contributed to this report