The first time around, Justin played a troubled youth whose brother was killed.
In his next appearance, on February 17th, his character "will call Nick (played by George Eads) to tip him off that he’s in imminent danger," according to TVLine.
JB tweeted about it saying:
"on set...where? let's just say Im back to my evil ways. #badass"
If you're a CSI or Justin fan, you will not want to miss this! ;)
Source: celebuzz