Matthew David Keirans, 59, of Hartland, Wisconsin, pleaded guilty last April to federal charges of aggravated identify theft and making false statements to a National Credit Union Administration insured institution.

The charges shocked Keirans’ family and friends, who described him in letters to the court as kind, gracious and dependable. His victim, William Woods, said Keirans’ guilty plea spelled the end of a yearslong nightmare.

Woods said Keirans tried to make him look like the criminal.

“He deserved to get every bit of what he got from the judge,” Woods said after the sentencing.

Court records indicate Keirans had a rocky childhood, ran away from home at 16, stole a car in San Francisco and was arrested in Oregon but never appeared in court.

The two men met in the late 1980s while working at a hot dog cart in Albuquerque, New Mexico, court records show.

Woods said Keirans stole his wallet in 1988, but returned it after Woods threatened to punch him.

But while Keirans had possession of Woods’ wallet, he used the information on Woods’ social security card to apply for a driver’s licence as William Woods.

At that point, “he’s got my name with his face on an ID card,” Woods told The Associated Press.

There is no record of Keirans using his real name or social security number after 1988. Court documents show he publicly assumed the name William Woods in 1990.

Over the years, Keirans married and had a child, all as Woods. He worked at the University of Iowa Hospital and used Woods’ ID to secure credit union loans in Iowa totaling more than US$200,000 (A$320,000), prosecutors said.

Woods, meanwhile, wasn’t earning enough to file taxes — around A$5000 a year at the time, but he wasn’t completely under the radar. In 2015, Yousef Saleh Erakat, a YouTuber known as FouseyTube, found Woods living on the street and created a series of videos with more than 1 million views each that document Erakat giving Woods food and paying for him to stay in a motel.

Woods used money Fousey gave him to pay for a credit-monitoring service, and learned that someone was racking up debt and opening accounts under his name. Outraged, Woods marched into a Los Angeles bank in 2019 and demanded an end to it.

“The guy is fraudulent,” Woods recalled saying.

The branch manager asked Woods a series of security questions that he was unable to answer because the answers had been set by Keirans. Then the bank called the police, court records say. Keirans, whom the bank believed was Woods, told police that no one in California had permission to access his accounts.

“Suspect entered bank and attempted to use victim’s personal identification to gain access to victim’s bank account,” the arrest report said.

The real Woods was then charged with identity theft and false impersonation.

Keirans’ attorney argued in a court filing that Woods tried to steal thousands of dollars from his client, and described Woods as a “wrongdoer whose own conduct should mitigate any sympathy felt for him.”

Woods is identified in court records from that time as Matthew Kierans, misspelling his tormentor’s name. There’s no record of how or why authorities came to identify him as such.

Woods told police the names of his relatives, and even offered to call the owner of the hot dog cart to prove his identity.

“They wouldn’t let me,” Woods said. He said the YouTube videos also proved his identity.

As Woods repeatedly disputed the identity authorities foisted upon him, a California judge found him not mentally competent to stand trial and sent him to a state mental hospital, where he received psychotropic medication, court records show.

Woods spent 428 days in county jail and 147 days in the mental hospital. He was released after agreeing to a no-contest plea — a case that has since been vacated. The Los Angeles County Alternate Public Defender’s Office declined to comment.

Freed, Woods began a crusade to regain his identity, filing a string of reports. When he reached out to the University of Iowa Hospital, where Keirans was earning more than US$100,000 a year (A$160,000), hospital security called the police.

Keirans initially told police that the victim “needed help and should be locked up,” federal prosecutors said. But a detective tracked down the biological father listed on Woods’ birth certificate and tested his DNA to confirm that Woods was his son.

“My life is over,” Keirans said, when confronted with the results.

Woods is now back living in Albuquerque where he works as a landscaper. He said he plans to seek compensation for his wrongful incarceration.

“My main goal,” he said, “is to rebuild my life.”