Just days after he was ordered by a Massachusetts' court to hand over DNA and fingerprint samples, James Lewis, 62, appeared on a local cable television program Sunday night to defend his innocence and promote his new novel -- ironically titled "Poison!"
Asked by Cambridge Community Television show host Roger Nicholson, who has previously interviewed Lewis, whether he would be willing to "admit it right now" that he is the Tylenol killer, Lewis refused.
"The only thing I can say to you is that you're totally delusional," said Lewis, who spent most of the interview talking about his book, which he says is a fictional account of poisoning deaths in a Midwestern city.
No one has ever been charged in the Chicago-area Tylenol poisonings but Lewis has always remained under suspicion. After the murders he served 12 years in prison for writing an extortion letter to Johnson & Johnson, the makers of Tylenol, saying that if they paid $1 million they could "stop the killing."
After his release in 1995 he moved from Illinois to Massachusetts. In February 2009 his Cambridge, Mass., home was raided by the FBI; agents were seen leaving with boxes of evidence and an Apple computer.
Lewis said in this weekend's interview that even though he has "nothing to do" with the murders he still thinks about the victims.
"I feel for those people every day for the last 28 years," said Lewis.
Lewis' attorney, David Meier, did not return messages left by ABCNews.com.
A representative for Johnson & Johnson told ABCNews.com the company is referring all questions to the authorities.
James Lewis' Extortion Letter Lands Him At The Center of Tylenol Investigation
In Sunday night's interview, Lewis said that had he known how much attention his letter would draw he never would have sent it.
"I never dreamed it would have any type of impact upon those ... the victims," Lewis told Robinson. "If I had, I would have never written it"
Pressed as to why he and his wife would have been subpoenaed for DNA if they are innocent, Lewis declined to comment, again bringing the interview back to his book, released online on Jan. 1. He described the book as "a chilling thriller."
Lewis and his wife Leann were ordered by the Middlesex Superior Court in Massachusetts last week to comply with a subpoena from a DuPage County, Ill., grand jury, and submit DNA and fingerprint samples, according to investigators.
According to the Daily Herald in Chicago, new scientific technology available to analyze a smudge on one of the original Tylenol bottles could help establish a link between Lewis and the crimes.
The paper, quoting an ex-state official involved in the original investigation whose name was not mentioned because he agreed to speak only with a guarantee of anonymity, said that "advances in DNA and fingerprint technology may make the 'smudge' evidence relevant today."
Suspect James Lewis Says Killer is Still 'Out There'
In addition to the extortion letter, Lewis remained of interest to the FBI during the investigation because following his arrest, he gave authorities detailed plans on how the capsules could have been injected with lethal doses of cyanide.
When asked about the drawings, he has claimed he was only trying to be a "good citizen" by giving authorities sketches showing how someone might go about injecting cyanide into Tylenol capsules.
"I could tell you how Julius Caesar was killed, but that does not mean I was the killer," Lewis told the Chicago Tribune in a 1992 jailhouse interview.
In a later interview, Lewis told Chicago's WLS-TV that he believed the "Tylenol murderer is still dancing in the streets."
The Tylenol murders changed the way foods and medicines are packaged in the U.S. Tamper-resistant packages became common after 1982, so consumers could be confident their products had not been contaminated.
Investigators at the time said whoever was responsible took Tylenol packages from stores, injected the contents with cyanide, and returned them to store shelves.
ABC News' Chuck Goudie contributed to this report.