As the show host attempted to turn the questioning toward non-fiction and Lewis' recent court-ordered donation of his DNA to Illinois authorities investigating the 1982 Tylenol poisoning murders, the interview became less congenial.
"Why would they need your DNA?" the CCTV host asked Lewis.
"I'm not going to comment on anything like that," Lewis responded.
The interview and the DNA submission by Lewis and his wife, LeAnn, come 11 months after authorities searched the couple's Cambridge home and seized evidence as the 1982 Tylenol tampering case was reopened.
Seven people were killed in the metro Chicago area after taking Tylenol capsules laced with cyanide.
The CCTV host asked Lewis about the case that has haunted investigators and victims' families for 28 years.
"So, if you could admit right now you actually killed those people... can you do that for me?"
"I think that the only thing I can say to you is that you're totally delusional," Lewis said.
Lewis repeatedly fired back that the only thing he would talk about was his new book that became available January 1.
The self-published book is not the only controversial work Lewis has written. He served 13 years in prison for extortion after writing a letter demanding $1 million from Johnson and Johnson, his wife's former employer, to "stop the killing" by Tylenol.
"I never dreamed it would have any type of impact upon those ... the victims," he said.
"If I had, I would have never written it," Lewis said of the extortion letter that officially landed him in the middle of the Tylenol murder case.
"Have you ever reached out to the families of the Tylenol victims?" he was asked.
"I feel for those people every day for the last 28 years ... but I have nothing to do with it," he said.
Neither Lewis nor anyone else has ever been charged with the actual killings. His alibi he has repeated, was that he was living in New York at the time of the Chicago deaths.
As the I-Team reported last week, a grand jury in DuPage County has been investigating whether Mr. Lewis was the Tylenol killer and considering evidence obtained via new forensic technology that was unavailable in 1982.