He’s portrayed real people before in Selma, Red Tails and Gifted Hands, the bio of surgeon Ben Carson. But Cuba Gooding Jr. has never played anyone as notorious as O.J. Simpson, whose infamous murder trial captivated—and divided—the nation in the mid-nineties.

We’ll see how well he’s taken to it when the 10-part miniseries The People v. O.J. Simpson: American Crime Story kicks off tomorrow night at 10/9c on FX. The Jerry Maguire Oscar winner didn’t hesitate to play the football star turned accused killer of his wife and her friend, heading an all-star cast that includes John Travolta, Courtney B. Vance, Sarah Paulson and David Schwimmer.

But he didn’t anticipate how much the role would mess with his head, as he explains in this candid interview.

“I’d be in that backseat and I’d go, ‘what the hell did I do to deserve to be here, right now, sticking that gun in my mouth,’ on take after take. Brutal.”

Did you follow the Simpson story and watch the trial two decades ago?
I didn’t watch any of the trial. I was filming a movie then. I just wasn’t into it. The only thing I remember is the chase and when he surrendered to the police. The next thing I paid attention to was the not guilty verdict. When I heard the not guilty verdict, I celebrated. I was like, “cool, there’s another black man that didn’t caught by the police.” And I felt the guilt for not grieving for those families and their loss, whoever killed them.

Were any scenes particularly difficult for you?
Yes, a few of them; we did the funeral scene and O.J kissed Nicole. And we broke for lunch and I just wept in my trailer. I couldn’t stop crying, thinking about what the families went through. The Bronco chase was another. [I’d be in] that backseat and I’d go, ‘what the hell did I do to deserve to be here, right now, sticking that gun in my mouth,’ on take after take. Brutal.

How did you get through it?
A lot of prayer.

No doubt it was hard to shake at the end of the day.
Some of it still is. It was one of those characters that you just can’t jump in and out of. You kind of live with it for a long time of dark sensibility. Being in that mindset for six months, it took me so long to slice that from my psyche. Plus the physical transformation: I put on 20 pounds. This was probably the hardest character I’ve ever played. It was six months of an emotional roller coaster.

Did you think about visiting O.J. in prison?
I had no desire to visit him in his present condition, being incarcerated, being a shell of a man. I have relatives and friends who are incarcerated, and it breaks a man’s soul and spirit. I knew that this portrayal in 1994 was a flamboyant, charismatic movie star/marquee athlete. So I’d use the research materials from that time period in his life, and I let that not only propel my research in terms of his walk, his gait, his physical appearance, but [also] that braggadocious, egotistical manner in which he carried himself then. That’s what I was looking to achieve.

How did you get inside his mindset?
I made some decisions based on what I think his motivations were. I just had to keep my mind blank, in terms of forming too firm an opinion about him. I don’t judge my characters. But I did come away with the understanding that I think he has a condition. I believe, when O.J. Simpson passes away, if they do an autopsy on his brain, they will find CTE concussion syndrome. If you looked at his relationship with Nicole and the violent nature of it, and these violent, angry outbursts, you will see a lot of things that are indicative of these athletes with CTE. He played high school, college and pro football. It’s a lot of abuse to take, and I believe the damage to his brain influenced him in a way that brings about this aggressive behavior.

Did your feelings about his guilt and the verdict change as you filmed this?
Every week, every new script, every new bit of information I got. Back and forth, back and forth. I’d think one thing, then I’d think the other. The question of his guilt is my own personal opinion. And I don’t want to have that reflected in when you watch my performance. So I leave that to myself.

Do you think that if this trial happened today that it would have a different outcome?
I don’t know. Luckily I don’t have to answer that question.

What do you want audiences to take away?
If you thought he’s innocent or guilty, and whether you still think that, you’ll know how they came up with that verdict, so we did our job.

Have you watched the episodes?
I haven’t seen anything. I will someday but it’s way too soon for me.

Photo courtesy of FX, Fox 21 TVS, FXP