A Texan who was gunned down during a standoff with Dallas police this week reportedly worked as a security guard for Rep. Jasmine Crockett.

The man, known by several aliases, including Mike King, was running Off Duty Police Services, which placed North Texas officers in jobs, CBS News Texas reported.

He also reportedly drove a replica undercover police car using license plates stolen from cars outside a military recruiting office.

Mr. King was wanted for impersonating a law enforcement officer, having claimed to be one while recruiting for his business. Authorities have not released his real name pending the ongoing investigation.

The fugitive’s alleged criminal history raises questions about how he juggled a double life while serving a security detail for a sitting member of Congress.

Mr. King barricaded himself inside a vehicle in the parking garage at Children’s Medical Center Dallas around 11:40 p.m. Wednesday, Dallas officials said at a Thursday press conference. He was forced out by tear gas, brandished a gun and was killed by a Dallas SWAT team.

No officers or bystanders were injured, and the hospital briefly went on lockdown.

Ms. Crockett, a Texas Democrat, had paid “Mike King” for security services, CBS News Texas reported, while he helped protect her in Washington and Texas. He frequently stood close to the congresswoman during her Senate campaign, which she lost this month.