K-Fed -- GUILTY of Felony Acting on CSI

TMZ has obtained photo evidence of Kevin Federline actually working, for a change. Britney's man was all smiles on the set of the CBS hit drama "CSI," where the star has scored a role on the popular crime drama. During the shoot, K-Fed found time to chat with an actual LAPD officer on set in between takes. Observers say officers were instructed to keep curious fans and the "Pavarottis" (sic) at bay.

Kevin plays a thuggish, arrogant teen who harasses investigators on the show, played by series regulars George Eads and Gary Dourdan (investigators Nick Stokes and Warrick Brown, respectively). Don't miss K-Fed's acting debut, set to air this fall on CBS.