I was watching an old episode of CSI and i could have sworn I saw Kellan Lutz as one of the suspects or something. ANyone know if that was really him? Cuz I wasn't sure

If you check on imdb.com you can find all the work he's done. And it does show him as a character in one episode, although I'm not sure if he's the same one as you've seen.

He plays in Csi and Csi Ny!

Yeap! That's him alright!

Check here link

Acted as Alex Hopper in 1 episode apparently.