He was entrusted with reforming a jail and allowed to transport prisoners on commercial airlines while carrying a gun. But had officials examined Jordan Jericho Bautista Gunter’s past more closely, they might have quickly discovered that he was not the cop he claimed to be.

In fact, he was a convicted criminal with a history of impersonating law enforcement officers.

After several months during which he appeared to be successfully carrying out his duties, the 26-year-old’s artifice unravelled when police became suspicious as he attempted to administer a urine test to a former inmate at his home. He was sentenced this month in San Antonio to 63 months in federal prison.

Gunter founded a company named Public Safety Partnerships in Texas in 2014, the same year he legally changed his first name from Forrest.

About four years earlier, court documents show, he had received a suspended sentence after pleading guilty to the possession of a concealed weapon in Maryland. A condition of his probation was that he could not have any law enforcement equipment such as handcuffs and uniforms.

He was given a 45-day sentence in 2011 when police spotted him in a restaurant with a bullet-resistant vest, a baton and an empty holster, the Maryland-based Herald-Mail reported.

Yet in 2015 his company was awarded a contract to operate and provide personnel for the troubled jail in Frio County, a large rural area south-west of San Antonio with a population of about 18,000. County officials eager for jail standards to improve incorrectly believed he had law enforcement credentials, seemingly taking him at his word.

Jose Flores, a county commissioner, refused to comment on Monday but appeared to concede to the San Antonio Express-News that Gunter had not been vetted. “It was a desperate deal. He came at the right moment,” Flores told the newspaper, adding: “At the beginning, it looked like a good thing, but it backfired.”

Gunter’s problems began on 10 January last year, according to court records. He and one of his employees handcuffed and detained a former inmate at a home in Pearsall, Texas, and demanded a urine sample to confirm that bond conditions were being met.

Gunter claimed the man failed the test and called local police to take him to jail. When police arrived, they discovered Gunter was neither a qualified officer nor licensed to carry firearms. They seized his Glock and charges followed. The next month, federal agents arrested him on the flight charge.

Gunter also had a side job in another Texas county: transporting prisoners, sometimes on aircraft – such as a Delta flight from San Antonio to Greenville, South Carolina, on 9 March 2015.

“Information provided in court at sentencing revealed that Gunter boarded not one, but multiple commercial flights, while transporting an actual prisoner as he pretended to be a law enforcement officer,” said a statement from the US attorney’s district office. By writing false details on a form he persuaded a Transportation Security Administration worker at the San Antonio airport that he was a law enforcement officer trained to carry a gun on a plane.

The state case is ongoing, but Gunter pleaded guilty in federal court last May to one count of illegal possession of a firearm and one count of carrying a weapon on an aircraft. The Express-News reported that during sentencing, it was alleged that Gunter had tried to hire a hitman with a view to arranging the murders of two witnesses in the Pearsall case, though he was not charged.

The prosecution argued in a court filing that Gunter’s motivation was the thrill of holding power over others: “Schemes of power. Schemes of danger. Schemes for his own economic benefit and psychological gratification. Each and every time the defendant illegally holstered a firearm and proceeded to exercise control over individuals – with handcuffs, loud commands, and the exhibition of those firearms – he placed them, and others, in grave danger.”

Gunter’s public defender, Jack Carter, said his client had been diagnosed with Asperger’s syndrome, which made him compulsively obsessed with being a member of law enforcement. Carter said Gunter might appeal against the sentence. The attorney said that to his knowledge, “nobody’s ever accused him of doing a bad job. It’s all been about acting like you’re a policeman, not having all the proper certifications, but I haven’t heard any complaints about how the jail was operated.”