To Catch a Killer : A bunch of cops and attorneys get together once a month to try to crack unsolved cases. It started out as a club, but could become a public service.

They found her lying at the bottom of a stairwell. She was on her back, fully dressed in jeans and a blouse, with a down-filled overcoat placed carefully over her body. She hadn’t been sexually assaulted, but her face showed the bruises of a severe beating, and the foam-like saliva coming out of her mouth was an inescapable sign of strangulation.

Whoever had murdered Deborah Wilson, a 21-year-old Drexel University student, had dragged her body from the computer room of the campus building where she worked, placed it carefully in the stairwell, then done a very curious thing: removed her sneakers and socks and took them from the crime scene. They were never found.

After Wilson was killed on Nov. 30, 1984, Philadelphia police quickly collected evidence, interviewed friends and relatives, and zeroed in on a prime suspect. But the physical clues were minimal, the circumstantial evidence not convincing. No arrests were made.

In the spring of 1992, the police are still looking for Deborah Wilson’s killer.

“You always feel bad about the cases you don’t solve,” says Bob Snyder, “the ones involving the young, the innocent and the aged. This is one of the innocents.”

Snyder, the Philadelphia homicide detective who has been doggedly trying to find Wilson’s murderer, is making these remarks before a most unique court of last resort--the Vidocq Society.

This little-known East Coast fraternity consists of homicide detectives, federal prosecutors, defense attorneys, FBI and customs agents, polygraphers and forensic scientists who pool their experience and intellect attempting to solve the unsolvable.

Named after a trail-blazing 19th-Century French detective, the 2-year-old society meets each month for lunch here. After an hour or so of schmoozing and food, members listen to a presentation by a homicide detective, private investigator or victim’s relative haunted by an unsolved murder case.

They listen to a recounting of the crime and look at the evidence. Then, in a free-wheeling session that is part question-and-answer, part brainstorming, they try to come up with new lines of investigation, new evidentiary avenues, new ways of thinking.

“It’s an intellectual pursuit, but I feel we can also perform a public service,” says society member Joel Freeman, a prosecutor attached to the U.S. Justice Department’s Organized Crime Strike Force here. “Part of what we’re doing is to formulate other avenues of pursuing these crimes, and that can be really difficult.”

“The longer a case goes unsolved, the less likely it is to be solved,” adds Frank Friel, a former Philadelphia homicide detective who has more than 4,000 murder investigations under his belt and now heads a suburban Philadelphia police force. “But homicide investigators always have cases they feel should have been solved and are not. That’s what this organization is about.”

The Vidocq Society originated at a lunch meeting involving a U.S. Customs agent, a Michigan forensic psychologist and a sculptor whose facial reconstructions have been used in crime cases. The three enjoyed talking about the cases they were working on so much that William Fleisher, the Customs agent, suggested they form a society to talk about unsolved crimes.

“The purpose was absolutely social--to bring people of common interests together to discuss things we enjoyed discussing,” says Fleisher.

He contacted friends in law enforcement and found that response was overwhelmingly enthusiastic. He then suggested the organization be named after Francois-Eugene Vidocq (1775-1857), an ex-convict who went on to set up the Surete, the French national police force.

(While going straight, Vidocq also invented invisible inks, experimented with fingerprinting, handwriting analysis, blood and ballistics tests and was the first to keep detailed files on criminals. He is also the inspiration for the detective in Edgar Allen Poe’s “The Murders in the Rue Morgue.”)

During its first year, the society was a social club. The membership--limited to 82, the number of years Vidocq lived--discussed cases brought by individuals and even indulged in past whodunits: It looked into the Cleveland “Torso Murders” of the 1930s, one of the first examples of modern serial killings.

But the tenor of the organization began to change when, last summer, Friel went to Corpus Christi, Tex., to address the national convention of Parents of Murdered Children.

“We had never thought of doing things pro bono for the public before,” says Fleisher, “but when Frank came back from Texas, he said it was so poignant, hearing from these people who didn’t know what had happened to their family members, and that we should start thinking in that way, helping.”

Law enforcement reaction to Vidocq has been generally favorable. The organization, which does not see itself as some sort of “super police” agency, goes out of its way not to become involved in active murder investigations. In fact, several of the cases tackled by the society have been taken to them by detectives who have run into dead ends.

Although most of the cases discussed by the organization come from the Philadelphia area, the society also gets queries from anguished people coast to coast. A Los Angeles man asked it to look into the 30-year-old murder of his father. A New Yorker called regarding an employee who had been beaten to death outside a disco.

In every case the society has heard--there have been eight--it was “obvious to almost everyone in the room who the culprit was,” says Fleisher. But the society has no official status. It can provide leads and advice, but members recognize that, in Friel’s words, “the reality of investigating in a large city is that your resources are frequently drained. Some cases will never be solved.” Nor has any case been solved because of the society’s intervention.

That’s why the Vidocq Society wants to organize teams of full-time investigators who can help solve murders on a pro bono basis. They’re looking into grant money, even the possibility of big bucks from movies or TV. In fact, the entertainment industry is salivating over the Vidocq Society, which already has been contacted by several major film producers. Last month’s meeting was attended by representatives of Republic Pictures and Fox-TV. The society will also be featured on “48 Hours.”

But these professionals are not about to go Hollywood. They’re hard-core cops and criminologists, serious about their mission.

“We do it not only to do what we’re doing now,” says Richard Walter, the Michigan forensic psychologist who is one of the group’s original members, “but to eventually have a network that could be used to go into jurisdictions as a group of experts. Our value isn’t that we’re super-geniuses. It’s that we can call on each other.”

Bob Snyder is standing at a podium in a large dining room of the City Tavern, the restaurant that hosts Vidocq Society meetings. Set on the podium are small French and American flags, a bust of Vidocq and Snyder’s bulging file from the Deborah Wilson murder. Facing him are about 80 attentive society members and their guests: a law professor, an author, a member of French Interpol, even a physicist who wonders if his work with aerospace circuits could be applied to forensics.

Snyder’s presentation is to the point. He describes the circumstances surrounding the finding of the body, Wilson’s last known movements and the comings and goings of the security guards inside the building where she was killed.

As Snyder talks, Bill Fleisher walks up and down the room, holding up pictures of Wilson’s body, of the type of sneakers she was wearing, of a blood stain found in the computer room and the type of computer she was working on when she died.

Snyder says the cops have had a suspect, who was a little shaky about his whereabouts during a certain part of the evening, and he failed part of a polygraph test. But polygraphs are inadmissible in court, and the circumstantial evidence is insufficient to make an arrest.

Then the floor is thrown open to questions:

“Was there a janitor on duty at the time?” No.

“Were there any arrests for burglary made on campus that night?” No.

There are questions about whether Wilson ever signed off on her computer (which could help pin down time of death). The members seem to be hitting a wall, until someone starts talking about DNA testing. This technique, which proponents claim is more accurate than fingerprinting, was not available when Wilson was killed. It’s suggested that if the cord used to strangle her was gripped tightly enough by the killer, there may still be traces of skin nuclei on its surface. This residue can be tested using DNA techniques.

It’s a long shot, but right now, Snyder is willing to clutch onto any suggestion. He’s frustrated by his inability to move the case forward.

Besides, the session has helped convince Snyder that he’s been on the right track all along. Before the meeting adjourns, Richard Walter gives a short psychological profile of the killer, describing him as “the power-assertive type, a macho guy who likes to dominate and control.”

You can almost see Snyder’s spirits lift as he hears Walter’s assessment.

“The profile,” he says, “fits my guy to a T.”