What Finn Wittrock Found 'Admirable' About Darren Criss' 'American Crime Story' Transformation
See the Real Life Players and Their On-Screen Counterparts

The actor also tells TooFab how he prepared to play one of Andrew Cunanan's victims, Jeff Trail, on the FX series.

Finn Wittrock gives one of his most powerful performances to date as real life Andrew Cunanan victim Jeff Trail on "The Assassination of Gianni Versace: American Crime Story," someone Wittrock admits he didn't know too much about when he signed onto the show.

The 33-year-old actor became a breakout star of the Ryan Murphy TV universe after his debut as murderous Dandy Mott on "American Horror Story: Freak Show" in 2014. He followed that up with two roles on "Hotel" and a barely-recognizable turn as a hillbilly cannibal on "Roanoke." For his most recent pairing with Murphy, however, Wittrock tapped into a completely different kind of mindset to play a military veteran and Cunanan's first victim.

Based on Maureen Orth's book, "Vulgar Favors: Andrew Cunanan, Gianni Versace, and the Largest Failed Manhunt in U.S. History," and written by Tom Rob Smith, the new season of "American Crime Story" explores the serial killer's past and the lives of those he killed, while highlighting the homophobia and gay panic rampant in the '90s. The Feb. 14 episode revolved almost entirely around Finn's character, showing how Trail spoke out about "Don't Ask, Don't Tell" in a "48 Hours" interview and delving into his complicated relationship with Cunanan (Darren Criss) before his eventual murder.

With Wittrock returning Wednesday night -- reminder: each new episode takes place before the last -- TooFab caught up with the actor to talk about the research he did for the role, what it was like witnessing Criss' transformation on set and how his storyline is still relevant today.

How familiar were you with the case beforehand?

I kind of knew as much as most people that I talked to I think. I kind of vaguely knew about the murder but didn't know much at all about Cunanan, and so it was a big education. I mean the book, Maureen Orth's book, was a huge piece of research for all of us and sort of created an incredible insight into that whole unfolding of the story. I think it's funny, I talked to people from Florida though, like anyone who is from Miami or almost anywhere in Florida. And everybody I've talked to is like, 'I know all about that.' It's like they know Cunanan, they know the other guys, they know the manhunt. I think for people who were living there at the time, especially around Miami, they got so invested in that story. It was like as big as OJ.

The show works backwards. What was your first day of filming? And did you guys film chronologically at all?

No. If there was a way to be the most opposite of chronologically, that's the way we shot it. It was literally all over the place. My first day I think was in the airport when we go to pick up Andrew. And then like the next day or the day after I was getting killed and then the day after that I was on the aircraft carrier. I mean it was like all over the place.

I like tore the script apart and I put all the scenes together in chronological order so that I wouldn't get confused. Like that death scene, is over the course of two episodes, so people were like, 'It's scene 96 in episode four, but it's scene three in episode 5' or actually vice versa. And it's like I don't even know what you're talking about. Tell me where to fall.

Is this different than it usually is for you? That's kind of what it seems like.

You know, I think any actor -- anyone who works in TV -- is used to it. I think because of the nature of the way the story was being told, I think like Tom Rob Smith had such an interesting structure out of working backwards like that. It kind of added a new challenge for everybody to kind of piece together where they were, what happened and you know. It's like you already shot the future so you have to make the past that gets to to that point.

And now I know some of these scenes, they're very serious or very dark. And when you are jumping around that much, how do you kind of get into the headspace for the day?

We trust a good script. If the arc of it is clearly defined in your head and you have people that you can really work with, then you can kind of jump anywhere and it doesn't really matter. It can even sometimes be fun to go towards the end of something before doing the beginning scene. You can kind of figure out how to build up to it. It's definitely a challenge, but there are perks to the challenge.

There is a lot of talk about Darren because he just loses himself completely into this role. What was it like seeing the light switch on and him becoming Andrew Cunanan?

It's so cool because he really did, sort of, it was like a mask he threw on and off when he was in it, when he wasn't. And I think it was maybe in some way the survival mechanism to not stay in it too much, you know. But it was really admirable to kind of watch him be his sort of buoyant energetic self and then sort of drop in at the drop of a dime to this sociopath. But he hates when you say sociopath. Understandably, because he has to play him.

Your character's storyline, Jeff's storyline, most of your solo episode was about 'Don't Ask, Don't Tell.' It's crazy to think we're still talking about similar bans, like the transgender ban, 20 years later.

It's so funny, when I first read the script I was like, 'Ahh, it's probably a little dated to talk about 'Don't Ask, Don't Tell.' And then like a couple weeks later that whole transgender thing came out.

I know you watched the real "48 Hours" Jeff did to prepare. What was it like the first time you watched it and kind of getting into Jeff's frame of mind at the time he filmed it?

You don't see his face. He does allow his voice, but like you don't see him. But you can see read so much off of him because he's so composed, he's such a put together, upright young man you know, who really believes in God and country, like really actually does and has a real patriotic feeling inside of him.

But you can also just tell that he's bursting out of his skin, like right underneath of that composure. So that, I mean I just watched it over and over probably for the physical elements of replicating his voice a little bit and that, but that's just also like hearing him and seeing him, you just really could feel by osmosis kind of internal struggle that was going on inside him.

"The Assassination of Gianni Versace: American Crime Story" airs Wednesdays on FX.

see side-by-sides Getty/FX 'The Assassination of Gianni Versace: American Crime Story' Cast vs. Real Life