Ed Gein, John Wayne Gacy

And like Hunnam, Chernus fielded his share of questions about why he took on the role of “Killer Clown” Gacy, who was found guilty of murdering 33 boys and young men in the 1970s and executed in 1994.

“With John Wayne Gacy, by all accounts, he was such a social guy, and sometimes described as even charming or likable or friendly in his normal day-to-day life,” Chernus explained to TV Insider in October. “I was interested in that duality of someone who could do such horrific, unthinkable things, but most of the time, comes off as a completely harmless, non-threatening individual.”

And it’s extra scary because it’s true. See Hunnam, Chernus and more actors who’ve tested their acting chops in killer roles: