Boston ? James W. Lewis has a habit of getting into trouble. And a knack for getting out of it, too.

He was charged with killing and dismembering a man in Kansas City, Mo., in 1978, but the case was thrown out. He was jailed on rape charges decades later in Massachusetts but went free when the victim refused to testify.

And while authorities in Chicago have long suspected Lewis was responsible for the deadly 1982 Tylenol poisonings, the only thing they ever pinned on him was an extortion attempt against the maker of the pain reliever. No one was ever charged in the seven cyanide deaths.

Now the FBI says there are new leads in the Tylenol case and on Wednesday seized a computer and boxes of files from Lewis’ Boston-area home. The mysterious and sudden flurry of activity has raised hopes of a long-awaited break in the sensational 26-year-old case.

Exactly why investigators have suddenly taken so much interest in the self-proclaimed “Tylenol Man” is unclear, but the FBI cited advances in forensic technology, along with publicity and tips that came in around the 25th anniversary of the crime in 2007.

Authorities have refused to release any further details of the investigation, including the whereabouts of Lewis, who is in his early 60s.

Tylenol poisonings

In a space of three days beginning Sept. 29, 1982, seven people who took cyanide-laced Tylenol in Chicago and four suburbs died. That triggered a national scare and a huge recall, and eventually led to the widespread adoption of tamperproof packaging for over-the-counter drugs.

Caught after a nationwide manhunt in late 1982, Lewis gave investigators a detailed account of how the killer might have done it, and eventually admitted sending a letter demanding $1 million from the manufacturer of Tylenol to “stop the killing.”

But he said he was only trying to exploit the crisis, and denied he had anything to do with the deaths. He was convicted of extortion in 1983 and spent 12 years in prison, getting out in 1995.

Police Commander Kenneth Galinski of the Chicago suburb of Arlington Heights, where three of the victims swallowed the lethal Tylenol capsules, said Thursday he is “cautiously optimistic” investigators have made a breakthrough, but would not elaborate.

Lewis’ background

Lewis’ life both before and after his prison sentence is full of strange and disturbing twists.

Police said that he was arrested in 1973 and 1974 for fighting with his stepfather and spent time in mental institutions.

In 1978 he was accused of dismembering a 72-year-old man who had hired him as an accountant. The charges were eventually dismissed because the cause of death was not determined and some evidence had been illegally obtained. Lewis denied killing the man.

He and his wife, Leann, moved to the Chicago area in the early 1980s, their activities shrouded in secrecy. Authorities said Lewis was chameleon-like in his ability to change his identity, using at least 18 names and posing as a freelance writer, real estate salesman, computer assistant and importer of Indian tapestries.

He was apparently haunted by the death of his daughter, who had Down syndrome and died at age 5 during heart surgery, and sometimes carried a recording of her voice, according to the FBI.

After getting out of prison, he moved to Cambridge with his wife.

Recent history

In 2004, Lewis was charged with kidnapping and raping a woman. He was jailed for three years while awaiting trial, but prosecutors dropped the charges after the victim refused to testify.

Lewis is listed as a partner in a Web design and programming company called Cyberlewis. On its Web site, he complains about being known as “the Tylenol Man.”

“Somehow, after a quarter of a century, I surmise only a select few with critical minds will believe anything I have to say,” he says in an audio clip. “Many people look for hidden agendas, for secret double entendre, and ignore the literal meanings I convey. Many enjoy twisting and contorting what I say into something ominous and dreadful which I do not intend.

“That my friends is the curse of being labeled the Tylenol Man. Be that as it may, I cannot change human proclivities. I shant try. Listen as you like.”

Looking for memoirs?

Lewis appears to be writing a novel titled “The Doctor’s Dilemma.”

“This is a novel about courage and integrity,” he writes on a Web site registered at the address that was searched Wednesday by the FBI.

Retired FBI agent Grey Steed, who worked on the extortion probe, said Thursday that he had been contacted by investigators to discuss the case.

“It wouldn’t surprise me if they weren’t looking for something in the way of memoirs or some type of journal he was keeping,” Steed said.