“It can be really hard to shut off.”

Frank Grillo’s TV credits include “The Shield” and “Prison Break” and such films as “End of Watch,” “Zero Dark Thirty” and the upcoming “Captain America: The Winter Soldier.” He discusses the challenges for actors in bringing violent characters to life.

When you’re filming a scene of a murder, is your preparation different than in preparing a scene of intense emotion?
I just did this film (“Homefront”) with Jason Statham about a bad-ass criminal who just got out of jail, so for something like that I spent some time in a prison and isolated myself with people who share that same mindset. The key is you don’t judge them or yourself when you put them in your head space. You try to fool yourself into thinking you’re violent. It’s harder to do that and be believable than it is to be super-emotional in a scene.

Have you ever had qualms trying to get inside the head of a killer?
Where your head goes your body follows. At some point you have to convince yourself you are not that person, and sometimes you just have to say “Don’t go there” because it is too tough to get out of your system.

Do you have to conjure up internal rage?
I go through specific things to get that built up. You have to prepare yourself to come down from that. It’s important to come down from that and not come home with that toxicity. I know a director who has a great script and has a bunch of top talent who have said no to it because of the kind of head place that they would have to put themselves through. Sometimes you have say stop because there is a possibility that it will be tougher to shut it down.

Does it take time to decompress?
It does get the best of you. If you are on a job and going home with that it can be really hard to shut off. There are times where my wife has told me to “Take that shit out of the house, don’t bring that in here.” It’s not like playing a cello. I really have to take the time and settle things down before I enter back into the real world.