CSI: Las Vegas season 15 has started production for its fall release. TV Guide has reported a new serial killer will shake up DB Russell's (Ted Danson) and the rest of the elite team.

Bodies killed in the same M.O. as a locked up convicted murderer's signature will reportedly start to turn up around Las Vegas as the alleged killer's execution nears. The serial killer named Mr. Briscoe, who was arrested years ago by Russell, will be found to have a secret twin brother.

The CSI Writers' Room had alluded to the series-long threat in early June, describing CSI: Las Vegas season 15 as "super dark and twisted."

"We're very excited about what we have planned for you this year. It's super dark and twisted," The Writers' Room informed the show's viewers through Twitter. They soon reassured viewers that although the next season will be dark, it will not be "painful" but will be "a fun season (and dark), but not painful. Fun!!! :)"

"Hey, did you guys want to do a season-long killer this year?" The CSI Writers' Room later asked its fans, possibly alluding to Mr. Briscoe.

CSI: Las Vegas season 15 started filming early to give way to its spinoff "CSI: Cyber" which was introduced last season with the sex video case.

The Writers' Room adds, "We are starting early this year so we can finish a little early, leaving time for 'CSI: Cyber' to air in our time slot."

Executive producer Carol Mendelsohn announced her leave from the Las Vegas leg of CSI to work on the cyber crime spinoff, staring Patricia Arquette.

The latest season reportedly is filming in an unconventional manner, starting with a yet untitled episode two instead of the premiere. Richard Speight Jr. from "Band of Brothers" and "Supernatural" will be a guest in the second episode.