The tapes are said to be grainy and poorly lit, typical of the kind of bargain basement surveillance tapes that are usually placed in convenience stores and service stations. There's no sound. But the tapes taken from the Amoco Station in Somerville in 1995 are clear enough.

If you look at them closely enough, it's easy to identify the man sauntering into frame as Nick Bissell. It's also easy to see him stroll over to the cash register and grab a handful of cash from the business he had purchased years earlier from his father and ran with the help of partners, among them Detective Thornburg's brother.

Admittedly, it doesn't look like a high crime. But according to federal prosecutors, it was proof that Bissell was skimming profits from the station. To them, the tapes depicted one step in a series of crimes that would ultimately prove to be serious enough to bring charges against Bissell and his wife of theft, tax evasion and fraud.

The feds were certainly closing in. If they had started their probe discreetly, they were now playing hardball. Among other things, they raided Bissell's comfortable Skillman Township home, seizing financial records and cash.

For the first time, Bissell seemed rattled. He emphatically denied to reporters that the search had taken place, but, in what would later be seen as a measure either of his panic or his unbounded arrogance, he demanded a meeting with federal prosecutors.

In a tactical mistake that amazes all of those who had watched Bissell's masterful legal performances over the years, Bissell refused to bring a lawyer along. In separate interviews, Bissell and his wife, who also appeared without an attorney, gave conflicting accounts of their finances and the finances of the gas station and other businesses.

What Bissell did not know at the time was that the federal investigators had at least one card they weren't showing.

Thornburg, Bissell's old friend, the man he had once appointed to head the "Internal Affairs and Employee Integrity Unit," the man he had hired to ensure that "there will not be detectives and assistant prosecutors involved in criminal behavior," had decided to do exactly what Bissell had hired him to. He became one of the government's chief witnesses against Bissell and his wife in a case that involved 30 counts of wrongdoing from fraud to misuse of authority.

Among other things, Thornburg had told authorities, and would later repeat in court, that Bissell had planned to frame a judge who had crossed him on a case. Thornburg said Bissell had ordered a detective to follow the judge home from a local bar with the intention of charging him with drunk driving. The plot, Thornburg noted, never came to fruition. But Thornburg's testimony elevated the case from a matter of simple tax evasion to an issue   of abuse of power.

Soon others came forward as well. There were allegations that Bissell had also threatened business associates, warning one, for example, that cocaine would be planted in his car if he didn't accede to Bissell's wishes.

By the time Bissell's trial began in April 1996, the house of cards that he had constructed had already begun to collapse. As soon as the indictment was unsealed, Bissell had been fired. His assets were frozen.

But there was more. In February, Thornburg's brother sued the Bissells, claiming they had embezzled money from him through the gas station.

A week before the Bissell trial began, Bissell's accountant pleaded guilty on federal charges that he helped the couple evade taxes. What's more, in the Guiffre case, the sordid little land for mercy deal that had started the prosecutor's downward spiral, had ended when the Somerset County Board of Freeholders had voted to approve a $435,000 settlement to Guiffre.

Despite it all, Bissell gambled again. Even when his wife begged him to let her cut a deal that would at least have spared her prison time, Bissell insisted on going to trial.

As he wrote in an August 15, 1996 letter excerpted later in the press "it was clear from the beginning that a plea would have allowed my wife, to some extent, to remain free and in a position to nurture and guide our children as they move through their teenaged years toward adulthood But as I've stated, I was committed to trial."

It was another bad bet.

On May 31, 1996, Bissell and his wife Barbara were found guilty on all counts. Despite all the evidence the government had arrayed against him, Bissell had permitted his defense to call only one witness. In typical Bissell fashion, that one witness was himself.