According to the Licensed Private Detectives Association of Massachusetts, which represents 450 agencies, business is up because crime is up. "When the economy gets rough, our business tends to increase," says executive director Phil White. "There's more crime of all kinds. People who can't make a living still need things, so the next alternative is to try to get away with stealing. We get called to do either criminal defense work or a company will call us to investigate internal theft by employees. We work both sides of the street."

Much of the work is civil, too. "Word leaks out that there are layoffs coming, and people have unwitnessed accidents," says John DiNatale. "It's, `I slipped on the floor and gotta go out on workmen's comp.' ... Insurance claims are going up. In a bad economy, there's more theft, there's more white-collar crime, and all of that means more business for us."

The only part of their business that hasn't grown during the recent economic meltdown is domestic surveillances, or spouses checking up on each other: "There's not enough extra cash to keep a honey on the side," says John.

Detective work is as much a part of the DiNatale family tree as their famed pasta with red sauce. Their grandfather Salvatore joined the Boston Police Department in 1919 and worked on the notorious Brink's robbery case. Three uncles were Boston police officers. And their father, Phillip, was one of the chief investigators on the Boston Strangler case. His sons have a box full of his letters from the then-imprisoned Albert DeSalvo, who had confessed to the crimes.

"Hi Phil," begins one four-page missive. It is signed: "Always yours, Al." The Boston Strangler terrified the city from 1962-64, when 13 women were slain in their homes. One of the largest homicide cases in history, it has long been the stuff of lore, with a movie and books devoted to it. DeSalvo was stabbed to death in prison in 1979. Phil DiNatale would visit him there and bring him books; DeSalvo had requested nonfiction, including books on science, psychiatry, law, and "snakes with pictures."

It was the Boston Strangler case, in fact, that led to the opening of the DiNatale Detective Agency. After the task force disbanded in 1965, Phil was assigned a desk job. Then Hollywood came calling: Director Richard Fleischer offered him a job as a technical adviser on a movie about the sensational events. The police department told DiNatale he couldn't accept the offer, so he quit. "The Boston Strangler," released in 1968, featured Tony Curtis as the strangler, Henry Fonda as head of the task force - and George Kennedy as Phil DiNatale.

When his movie gig was through, DiNatale opened his own detective agency in downtown Boston and called on his sons to help out. While other teenagers were bagging groceries, Richard and John were helping bag bad guys. When their father died in 1987, they took over.

John DiNatale never intended to spend his career there. He was earning a master's degree in 20th-century Russian history when his father had a heart attack. So he went to work fulltime at the agency. Richard's path was more direct: He majored in criminal justice at Northeastern University. John's wife, Dorothy - whom he met when she was an undercover agent investigating employee theft - is the office manager. Three more detectives round out the staff.

Last year the agency handled 600 cases, doing background investigations for accidents, murders, rapes - "the stuff that happens regardless of the economy," says Richard. What's different now is the increase in white-collar crime - such as the lawyer who recently claimed that he had a psychological disability that prevented him from working; anxiety left him unable to go into a courtroom.

"This is the white-collar aspect of fraud; professionals claiming that they're psychologically disabled," John says. Hired by the insurance company, the DiNatales trailed the attorney and found him working two jobs while collecting disability.

While the subprime mortgage crisis has financially crippled so many, it has supplied the brothers with a steady stream of business. One recent case involves a Dorchester property assessed at $225,000; the buyer got a mortgage for $375,000, on which he defaulted. When the mortgage company realized it wasn't going to collect on the loan, the DiNatales were called in to investigate for possible fraud.

The agency has also been hired by a law firm representing investors who are suing a hedge fund that lost their money. The firm wants a background investigation on those running the fund and how they run it. "It's a whole new avenue of business for us," says John.

On a recent cold morning, Richard DiNatale and his colleague Matt Pileski head outside Boston to stake out "an individual," in cop terms, who was injured in a car crash. The man claims to be seriously injured and is seeking a big settlement from an insurance company. Three hours later, the target emerges from the staked-out apartment and heads to his office 10 miles away. Pileski shoots video: The man walks with no limp or stoop and puts in a full day's work. Bingo.

Of course there are other times when they learn that the claimant is telling the truth: He's laid up at home, on crutches when he does emerge.

The brothers work both for those seeking personal injury awards as well as for those seeking to neutralize such claims. Richard recently wrapped up work in the case of a woman who lost a leg after being hit by a bus. "I found a spectacular witness, who was standing there waiting for the bus," he says. She testified and the victim won a sizable sum.

As for that Russian history degree John holds, it has actually come in handy on the job, once. Some Russian clients were sitting at his conference table, discussing DiNatale's retainer. He had asked for $3,000, but - in Russian - the men agreed to offer $1,500. DiNatale interjected, in Russian: "I'm not taking $1,500" and proceeded to explain why. The clients were dumbfounded. DiNatale got the three grand.