"We're a network that likes to take risks," he said at the Television Critics Association winter press tour on Sunday.
Also read: Charlie Sheen Q&A: What He's Learned
Landgraf says the network generally doesn't pick up shows that haven't shot pilots, but made an exception for "Anger Management" in part because the show is inexpensive to produce. Lionsgate, the studio behind it, covers much of the cost, he said.
Landgraf is known for giving FX shows an unusual degree of creative freedom, and "Anger Management" has even "more leeway and more creative freedom than most," he said. He stressed that the network didn't just pick up the series to exploit Sheen's notoriety.
"I walked into the pitch as skeptical as you might imagine I would be. Charlie was there, as was the creator the and showrunner [Bruce Helford]. It was just a really excellent pitch," Landgraf said.
He noted that Sheen had turned up the weekend before at a party where he was decidely more mellow than he was in media apprearances last year.
"I think some of you saw Charlie last weekend and I think you saw a very different Charlie Sheen than you had been seeing in the press through the whole end of his relationship with 'Two and a Half Men.' And I saw that guy," Landgraf said.
"And what I heard was a really good pitch for a comedy series," he added. "Funny, complicated, and I think the character that Charlie ought to be playing at this point in the sense that he is a character who has a checkered past but is pretty self aware, is struggling in a very honest way with that checkered past and desire to do more positive things in his life."
Asked during a Q&A whether Sheen deserves a place on television given his past violence against women, Landgraf said the character on the show was trying to improve himself, as Sheen is in real life. The character has a positive relationship with his ex-wife and is trying to raise his 13-year-old daughter.
"I believe in redemption," Landgraf said.
In other FX news, Landgraf said the network has not picked up the pilot for the comic book adaptation "Powers." But he said the network is reconsidering it now that it has been largely rewritten and reshot.