CSI: Crime Scene Investigation will start season 15 off with a blast from the past - Russell's past that is.

CSI: Las Vegas' Romance In Store For Russell & Finlay? Past Spills Out With Mark-Paul Gosselaar's Serial Killer Case

D.B. Russell locked away the Gig Harbor killer years ago, but a mysterious phone call will make him doubt his work during "The CSI Effect."

The Las Vegas team will be in for double trouble when Franklin & Bash's Mark-Paul Gosselaar takes on the roles of Jared Briscoe and Paul Wintrhop - the alleged Gig Harbor killer and his mysterious twin brother. Separated at birth, the appearance of this new twin and a copycat killer will complicate the fate of the original alleged killer.

'CSI: Las Vegas' Spoilers: Bella Thorne, Mark Valley Cast For Season 15, Valley Has 'Undeniable' Attraction With Which CSI?

Don't expect the problem to be solved anytime soon, however.

"Hey, did you guys want to do a season-long killer this year?" the CSI Writers' Room asked in early June, teasing Gosselaar's continuing role.

In the meantime, Finlay will have her own issues - particularly a mysterious car bomb.

Find out more when CSI: Las Vegas returns to CBS for a 15 th season this fall. Click the video below to see a preview from the series latest episode.

Tags
CSI: Crime Scene Investigation, Television, CBS