It’s been 25 years since the crimes of Jeffrey Dahmer shocked the world and now, in a two-night special airing on Oxygen, Investigative Journalist and Philadelphia native Nancy Glass reveals what it was like interviewing this cold blooded killer and examines the phenomenon of how he got away with so many murders over the years.

He killed people, dismembered them, and he even cannibalized them. Twenty five years ago, Nancy recalls sitting across from Jeffrey, “when I sat opposite him and saw how normal he appeared that what was unnerving… What’s much more chilling is somebody who can fool you.”

She reveals topics they cover from all those years ago where Dahmer talked about his regret, wanting forgiveness, and about the impulses he couldn’t control.

Above it all though, Nancy is clear that even after interviewing and speaking it is unclear what is all true. “The fact is he was a psychopath so who knows if what he said was what he really meant.”

You can catch the full Oxygen Original, “Dahmer on Dahmer: A Serial Killer Speaks” starting Sat Nov 11 at 7/6c.