CEO murder suspect's ex-roommate stunned by charges: 'It's like two completely different human beings'

The former roommate of Luigi Mangione, the alleged killer of UnitedHealthcare CEO Brian Thompson, said he "feels strange" about the Ivy League graduate’s arrest because he knew someone who was "completely different."

R.J. Martin told "Jesse Watters Primetime" on Tuesday that he was roommates with Mangione for six months at Surfbreak Coliving in Honolulu, a self-described "co-working space for remote workers and digital nomads."

"The entire time that he [Mangione] lived at Surfbreak, he was a great community member. He kind of followed by our values and our ethics to leave things better than you found them. He was always contributing, taking care of other people. And even after he moved out, he came and hung out and contributed to the community, spearheaded a book club," said Martin. 

He added that the two became close friends, worked out together and played volleyball together.

"He's the kind of guy who was doing his best to take care of himself despite having some severe back pain and a, you know, a severe issue," Martin told Fox News host Jesse Watters.

UNITEDHEALTHCARE CEO MURDER SUSPECT LUIGI MANGIONE COMPLAINED ABOUT BACK SURGERY BEFORE SLAYING

Mangione was arrested by police at a McDonald’s in Pennsylvania and held on a slew of charges before New York prosecutors filed a second-degree murder charge against him late Monday night in the shooting death of Thompson. 

FAMILY OF UNITED HEALTHCARE CEO SHOOTING SUSPECT SAYS THEY ARE ‘SHOCKED’ BY SON'S ARREST

Martin said he suggested his former roommate and other book club members read Unabomber Ted Kaczynski’s manifesto, explaining that at the time, it was a sort of "half joke." 

Mangione reportedly described Kaczynski's writings as "interesting," although Martin denied turning the 26-year-old toward the notorious murderer.

"I feel strange because he was a great friend and I consider him a close friend and that somebody who would assassinate somebody is completely incompatible with the person that I lived with, the person that I cooked meals with, the person that, you know, was part of book club and other activities with," Martin said. "It's like two completely different human beings."