It was the coldest of cold cases.

A John Doe beaten up and left for dead in a park in the Bronx lay in a coma for 10 years, unclaimed and unvisited, shuffled between city hospitals, until his death six months ago. But then the other week there was a breakthrough born of new technology – a national digital fingerprint database. The John Doe turned out to be a young former Greenwich, Conn., city councilman named Henry Davis.

Davis had been a novelty act in local politics. His family was from the public housing projects that few people know exist on the outskirts of the manicured suburbs of Greenwich. He was a local character – Greenwich cops recall him hanging out at their precinct, eagerly asking questions, running out to get them coffee.

In 1993, at the age of 23, Davis decided to run for what is called – with a hint of lockjaw – the Representative Town Meeting. It was a curiosity campaign, with handmade signs and inside-joke enthusiasm. Much to everyone’s amazement and amusement, Davis won. He served a single term, from January 1994 to December 1995 – not even worth a local Trivial Pursuit question. Nonetheless, his rise should have been a cause for family pride, the beginning of something bigger. It did not turn out that way.

When he disappeared one night in the summer of 1996, Henry Davis’s family failed to report him missing. They had moved down to North Carolina a few years before and lost touch or lost interest. The local sheriff in Hendersonville, N.C., told investigating police from New York this year that the family would always tell him that everyone was doing just fine.

But Davis was not fine. He was six months dead and buried. It was only a victim services group that saved him a burial in the group graves and cold ground of Potter’s Field.

It was a long fall from the Greenwich City Hall. Ten years ago, in July 1996, Davis had been found beaten unconscious outside a gay hustle zone near Yankee Stadium known to local police from the 44th Precinct – with their sanity-saving dark humor – as Pickle Park. The last person he’d spoken with told the police that Davis said he was a visiting Bible student from down South. No word on whether they discussed any relevant passages. Minutes after their acquaintance, word spread up the rambles that there had been an attack – a gang assault or gay-bash. It was unclear. And Davis wasn’t talking.

With no wallet and no missing-persons report filed by the family, Davis slowly faded from memory. An inconvenient heartbeat kept his body breathing in public hospitals on the public dime. From age 26 to age 36 he lay in hospital rooms from Bellevue to Roosevelt Island, forgotten. The case was never quite closed, but it was not exactly open either.

With Davis dead and the case transferred from an assault to a homicide, detectives began doing their due diligence. A clean original set of fingerprints was run through a new national computerized fingerprint database made available by the FBI to the NYPD after the attacks of September 11. It turned up a match – in addition to being a local character and Greenwich city councilman, Davis had passed a bad check or two in his day. That transgression helped ensure his identification, and may yet help find his killers.

Now there is a search on, of sorts, for his attackers. Few would hold out hope, but that’s the detective’s duty – to keep pursuing criminals in defense of justice and the dignity of the dead. There is some reason to hold out hope: Witnesses come forward, consciences catch up.

Here is how breakthroughs in cold cases can occur: Anyone who was walking from the Yankee game around midnight in McCombs Dam Park that July night in 1996 and saw what looked like a fight should understand that it was an assault that led to murder, and then call the 44th Precinct at 718-590-5537 or the citywide Crime Stoppers line at 800-577-TIPS. Even if it is a difficult case, the police are halfway there. After all, hope is more than Henry Davis had just two weeks ago.

Cold cases are never closed, and now the case of Henry Davis sinks into a deeper kind of mystery. With the possibility of saving his life now out of reach, it is still possible to redeem some of his suffering. John Doe has his name back – bringing his attackers to justice would bring a deeper resolution to this strange New York story.