For L.A. Police Detective, Crime Sometimes Is a Pretty Picture : Forgeries: Bill Martin is the only full-time art cop in the nation. He chases after swindlers in America’s second-largest art market.

A sting operation nabs an art dealer selling a forged Renoir for $3.2 million. Detectives discover a stolen George Washington portrait at a private home. A broker faces prison for pandering pilfered lithographs.

None of these cases would have been prosecuted a dozen years ago. But Los Angeles Police Detective Bill Martin has changed that. As the nation’s only full-time art cop, Martin tries to snag swindlers and thieves in America’s second-largest art market.

Martin has pushed the annual recovery rate for stolen and forged artworks in Los Angeles from zero in 1979 to 30%, about three times the national average.

He said he investigates 10 to 15 cases a month. Every case in Los Angeles crosses his desk.

Most investigations require tracing suspects far beyond the city limits. Martin’s investigations have touched Italy, France, England, Sweden, Japan and Honduras.

Right now, he’s on the lookout for the culprits who absconded with $200 million worth of Rembrandt, Vermeer and Degas masterpieces )from Boston’s Isabella Stewart Gardner Museum.

Working with the FBI and Interpol, he has launched a global manhunt for an auctioneer who claims to be a member of Hungarian royalty. The suspect is accused of skipping Los Angeles with more than $1 million of consignment art in a case that ranks as the city’s largest recorded theft of collectors’ items.

Martin got the notion to form an art-crime unit while working with a squad of 14 officers assigned to monitor professional burglars.

“I noticed we were recovering a lot of business machines. We were recovering a lot of jewelry,” he said. But the police headquarters’ wooden pigeonhole labeled “collectibles” just kept filling up with reports that never got handled, he said. “It was this kind of black hole.”

So Martin asked around for advice on how to tackle art crimes. Within one year he salvaged $1 million worth of art.

Then partner Jerry Sparks came on board. Together they recovered nearly twice that amount in 1991.

They work out of an office that would pass for an old-fashioned newsroom, minus typewriters, in Parker Center police headquarters. Thousands of dollars worth of real and fake art that they have uncovered is stashed at a warehouse, a treasure trove whose location is kept secret.

Martin’s work, in a market second only to New York, is a boon, the owner of Los Angeles’ oldest gallery said.

” . . . The very fact that there’s a unit (in art crimes) here has discouraged some people from going into fraudulent prints,” said Benjamin Horowitz, past president of the California Art Dealers Assn. and owner of the Heritage Gallery.

Formerly, Horowitz said, the police didn’t bother to check into claims of fraudulent art, even though “the reputation of the art world depends on the (integrity of) dealings between the art buyer and art dealer.”

Martin said he wasn’t an art buff when he started working on art crimes.

“It just kind of intrigued me, where all this stuff was going. What got me involved was the mystery,” he said.

To bone up on art history, he took classes from UCLA and from art auction houses.

“Now I learn as I’m working on each case,” Martin said. “I learn from my victims or from galleries.” He also consults with artists such as Hiro Yamagata and David Hockney, who live in Los Angeles.

With 5,000 pieces worth about $2 billion reported missing annually in the international market, the art world provides a mounting challenge Martin relishes. “It’s not like when somebody loses a stereo or even a diamond ring,” Martin said. “What’s nice about art theft is that so many pieces that you recover are antiques that are part of history and are irreplaceable.”