Have you enjoyed playing Nick's most recent storyline? He seemed to almost have a mental breakdown.
"Yeah, and I want to continue that. It makes sense that this job would wear down on these guys and I've tried to have a few moments where Nick has these emotional asides with the audience."
Is it a challenge playing Nick, since he tends to get quite emotionally involved with a lot of his cases?
"Yeah, it can be challenging. But, I mean, these guys [who work as CSI's] cannot see death every day like they do, and not have it affect them. So I enjoy the fact that Nick gets emotionally involved."
What's coming up for Nick later this season?
"He's pretty much going to get sick of people attacking him for just doing his job. Nick doesn't get upset by this, he gets mad! It's like, 'How dare you attack me when I'm just doing my job, protecting people?!'."
Nick's known as a bit of a ladies man, so is there any chance he'll get a love interest any time soon?
"I get that question a lot. Everyone always says that Nick's known as a ladies man, but we never see him with any women! Except we saw him with a prostitute! I think if they were to do that, it would have to work organically with the episode or the season when we were doing it. I wouldn't want to just put it in there for no reason. It would have to be organic."
How has it been working with Justin Bieber this season?
It's been great. He's got his film coming out [Never Say Never] I think in March, but when I originally worked with him, I didn't realise what a child prodigy he is! When we were shooting that first episode, I didn't think of him as a musician, I just thought of him as an actor. He was great to work with and just a really sweet, down-to-earth kid."
"Well, he's cast as this troubled teen, which is ironic, because it's kind of the opposite of what everybody knows him as. But he's back, causing trouble, and we have a face-off. Unfortunately for him, I'm the series regular!"
How has it been working with Laurence Fishburne, who has been a regular on the show for over a season now?
"Yeah, I've been working with Laurence Fishburne for almost two years now. It's great for me to work with him because he is one of my acting heroes and he's one of the reasons I got into the business. It's like a musician getting to go up on the stage with Joe Satriani! When Laurence first started, I told him I was a little bit scared of him, because the characters he plays are always intimidating! But he's a really generous actor and a really nice guy. I've learnt a lot from him."
Having played Nick for over a decade, do you have much input into where your character goes?
"I've always had input, pretty much from season two onwards. But even more since Billy [Peterson] left, the producers want to hear where we see our characters going. We're at the stage now where I can call them up if I have ideas about dialogue or something I'd like to change, and they're not going to shout down the phone at me!"
Now that CSI is in its 11th season, what do you think has kept the show fresh for so long?
"I think it's the actors who still enjoy getting up and going to work on the show. The show has such a loyal audience in the US, not to mention internationally. We have a huge audience internationally. That support makes it easy to get up and go to work every morning!"
The 11th season of CSI continues on Thursdays at 9/8c on CBS. CSI: The Complete Season 10 is currently available to buy on DVD.
Are you a loyal CSI follower? Excited about the Bieb's return? Sound off below!