A longtime Minneapolis official charged criminally with misusing driver’s license data is off the hook after a judge tossed the case and prosecutors said problems with state law hindered them from pursuing it further.

Tom Deegan, the city’s former chief of housing inspections, was one of the most visible officials at City Hall until he was charged in September with accessing driver data repeatedly without an authorized purpose. He ended his 37-year career with the city in January.In his first interview since being charged, Deegan on Wednesday called the decision an absolute victory. “Everything they said was proven unfounded,” he said.

Misuse of the state’s drivers and vehicle services (DVS) database by public employees is common across the state, state records show, but only a handful have been charged criminally. The Deegan case has likely advanced farther than any other, but a judge’s ruling exposed problems with a core statute that prosecutors used.

Deegan was charged solely with misconduct of a public employee, a gross misdemeanor. The judge in his case, Laurie Miller, wrote it is unclear whether that state statute covers violations of federal law, such as misusing driver’s license data. State law protects DVS data, but key statutes are linked to federal law.

“The judge saw some vagueness in the statute that could make it more difficult for us to be successful,” said St. Paul City Attorney Sara Grewing, whose office is handling the case. “We charged the case with facts that we believe are true.”

The decision could have implications for other attempts to prosecute DVS misuse across the state. Grewing said she will have meetings next week at the Legislature — which is already tackling tighter regulations around data misuse — to recommend clarifying the law.

Earlier this month, Miller dismissed the brief initial complaint against Deegan because it was too vague. The judge gave prosecutors a week to file a new one. After saying they would refile, prosecutors later opted not to proceed.

Deegan’s attorney, Paul Engh, said the complaint was “clothed by opacity” since it did not provide any details about specific instances of misuse. Engh argued that at least 40 employees had misused the data but were not prosecuted, adding that some employees had used Deegan’s password.

The judge ruled that Deegan had not proven he was being selectively prosecuted, however.

“The reason she didn’t rule on the selective prosecution is because I didn’t give her the names, that’s why, the names of my colleagues in the Department of Regulatory Services who were doing what I was doing and have continued to do what I was doing when they investigated me,” said Deegan, who also served as the city’s fire marshal and deputy fire chief.

He said that members of the city’s traffic control division and Public Works department had also looked up names for personal reasons.

“Our point was that Minneapolis police did not do a thorough investigation,” Deegan said. “It is common practice. If you did a thorough investigation, why didn’t you look at these people?”Since he left the city, Deegan said he has been rehabbing other properties outside Minneapolis for resale, has done some consultant work and may do more.

Deegan said that he did look up information about his mother, who died in 2008, and his brother, who died in 2000, because he was the executor of his parents’ estate and needed to clarify some information. He had limited access to data, so he could not look up people’s photos, for example. But he said he had not looked up anything since May or June of 2011.

He named several of his supervisors, who he said knew he was using the computer to look up the information, and a human resources official also knew “everybody is doing this. … It was common knowledge.”

“If they had something, why didn’t they recharge me?” he said. “Because they didn’t want me on the stand naming all these names, and they would have to explain why they singled me out. ... The courts found there was no substance to their case so they dismissed it.”

Grewing contended prosecutors could have easily elaborated on their complaint. “We wouldn’t have charged it if we thought there was an issue with gathering the details,” said Grewing, whose office has been largely alone prosecuting DVS criminal cases — defendants usually agree to lenient plea deals.

eric.roper@startribune.com 612-673-1732