"We're thrilled for Jorja's return to 'CSI,'" executive producer Carol Mendelsohn said in a statement Monday. "The viewers and longtime 'CSI' fans will be excited to discover where life has taken Sara Sidle and what brings her back to the 'CSI' team in Las Vegas in our premiere episode."
"CSI" will begin its 10th season this fall.
"Fox, who had been a series regular since the show's first season, left during its eighth season, when her character, Sara, suffering job burnout, decided to leave the crime lab to deal with past demons," CBS said in a news release. "She returned briefly during Season 9 and then left again to do research in Costa Rica, where her former boss and romantic partner, Gil Grissom, later joined her."