Paul Walter Hauser on ‘Black Bird’ co-star Taron Egerton

Acclaimed actor Paul Walter Hauser (“Richard Jewell”) is also a movie buff — so it’s no surprise that he describes his Emmy-worthy turn as “Black Bird” serial killer Larry Hall in cinematic terms — including Hall’s “Vincent D’Onofrio in ‘Full Metal Jacket’ stare.”

“I’d say for my process … is that if I treated [the role] some other way it takes the humanity out of it and I’m kind of leaning into this tendency to overact,” Hauser, 35, told The Post. “So rather than be like, ‘Wow, I’m playing a serial killer so I better get ready’ … [Hall] was a human before he was a murderer, before he was a rapist, so you don’t want to play a killer like a killer. You play [him] like a human — and that’s where you get Alan Rickman in ‘Die Hard’ or Christoph Waltz in ‘Inglourious Basterds.’

“These villainous roles are always better when there’s some sort of human element,” he said. “There’s another world where Larry Hall owns a body shop and cooks a vat of chili that he brings into a dive bar on Monday nights to watch football.”

“Black Bird,” streaming on Apple TV+, is a six-episode series based on James Keene’s 2010 autobiographical novel, “In with the Devil.”

Golden Globe winner Taron Egerton (“Rocketman”) plays Keene, a high-level Chicago drug dealer who’s busted by the FBI and sentenced to 10 years in prison. He’s offered his freedom, but only if he transfers to a maximum security prison and wrangles a confession from Hall — a high-talking Civil War re-enactor with mutton-chop sideburns who’s suspected of killing as many as 14 young girls.

Hall claims his prior confession to one of those murders was coerced (they were just “dreams,” he says) — and he could be free to kill again if his appeal is upheld … so Keene is on the clock.

Hauser said he “found a couple of YouTube videos” with “about 12 seconds of composite audio” of Hall’s voice. “It was very high and strange and sounded like a cartoonish voice,” he said. “I tried to bring him from a 10 to an 8 to make it more palatable for the audience. It does go up and down based on what he’s saying. I think when he’s lying it has a tendency to go ever higher and there are moments where you can tell he’s just kind of being himself with his guard down — and his voice is lower.

“I did the least amount of research of any character I’ve ever done, almost. I did more research for [his roles in] ‘BlacKkKlansman’ and ‘I, Tonya’ than I did for Larry Hall,” he said. “It’s really about [‘Blackbird’ executive producer/writer/showrunner] Dennis Lehane’s brilliant writing and then my creative ownership taking hold of what’s there. There are different things, like the way I move my tongue in the show, the vocal choices, me taking a bite out of the middle of a piece of bread and then sticking my finger through it like it’s Play-Doh.

“For me to know where Larry grew up or what size shoes he wore, those things don’t really help that much,” he said. “At the end of the day, your imagination is better than any Wikipedia page.”

The bulk of the series plays like a choreographed dance of wills between Keene and Hall — a mental ballet that eventually explodes into a physical confrontation between them in the series finale.

“By the end of the shoot Taron and I were exhausted and emotionally spent,” Hauser said. “I’d lost 40 pounds to play Larry and had to keep it off in New Orleans, and Taron sculpted his entire body and put muscle on and had to keep it on the entire time. Taron and I love each other very much [but] when you’re doing these roles together for six months, it does take a toll where you’re like, ‘We might need a break.’

“By the end, we were ready to tear each other apart, even though we were just playing characters.

“If that moment [in Episode 6] feels emotionally charged and chaotic, that’s because it was,” he said. “That’s how we were feeling — it was reality bleeding into the story.”