The CSIs question the validity of an online picture depicting a murdered call girl until they find the same woman strangled to death in the dumpster that appears in the photo.

A gunman opens fire at a local college, sending mass casualties to the hospital; Arizona's return is not warmly received.

Episode info coming soon ..

Leonard's idea for a smartphone app derails his friendship with Sheldon.

Neil deGrasse Tyson explains how tides work, and Robert DePinho wants to reverse the aging process.

With guests Gary Sinise and Alex Kingston. Plus the TV debut of the "Doctor Who" opening dance number which didn't air as originally planned during the Matt Smith episode.

Patrick and the team investigate the murder of a woman with ties to one of the fighters. Meanwhile, LaRoche focuses his investigation on Rigsby, who in turn is forced to ask Cho for a huge favor in order to keep his job.