Democratic U.S. Rep. Jasmine Crockett on Monday confirmed that a 39-year-old man who was killed in a standoff with Dallas officers last week was a member of her security team who had been using a fraudulent identity.

Diamon Mazairre Robinson lived as “Mike King” for years, during which he operated security businesses that hired off-duty officers, Dallas police said during a Monday press conference. Robinson’s real identity was exposed after Irving police put out a bulletin for a vehicle with stolen government plates, which a Dallas officer had seen while working with Robinson on a security job six months earlier.

Robinson fled Dallas police, who attempted to pull him over on March 11, escaping a brief chase before being located once more in a hospital parking garage, officials said. After an hours-long standoff with negotiators, officers shot and killed Robinson after he stepped out of the vehicle and drew a handgun.

In a statement posted on social media, the Dallas congresswoman confirmed that Robinson had helped provide security for her for years, and said her team had followed U.S. House procedure for contracting security. She also said Robinson, acting as Mike King, had worked with multiple law enforcement agencies, including Capitol Police. A spokesperson with the Capitol Police did not respond to an immediate request for comment.

Crockett said that her team was unaware he had been acting under an alias, but that Robinson had always maintained positive community relationships and never gave anyone reason to suspect he had misconstrued his identity.

“What we’re learning about his past doesn’t fit the person we came to know as Mike King,” Crockett said. “ His death evokes a range of emotions. Our hearts grieve the loss of someone we knew and the lost good that could have come from his redemption.”

DPD Deputy Chief William Kenneth said investigators did not discover Robinson’s true identity until after Crockett’s campaign for the Democratic nomination in the U.S. Senate race had ended. Crockett, a former public defender, said in her statement that she believed in people’s capacity for redemption and second chances. She also acknowledged Robinson’s prior criminal history and said they did not believe he had been charged with any violent offenses.

Robinson had posed as a federal officer under the “Specialty Dignitary Police,” a nonexistent agency he created identification cards for, officials said. He also had two active felony theft warrants from 2017, a parole violation, two vehicles with stolen government plates and multiple stolen firearms, including the one he produced before being shot, Kenneth said.