From CSI Files:
And some more detail in an article on the Hollywood Reporter site.
Paul Guilfoyle first appeared as Captain Jim Brass in CSI: Crime Scene Investigation’s pilot episode, and he has remained on the crime drama for the past 14 seasons. As CSI Files previously reported, the series has been picked up for a fifteenth season, but the Hollywood Reporter just announced that Guilfoyle will not be part of the cast when CSI returns in the fall. Producers made the decision to write the character off the show, and Guilfoyle will make his final appearance during the season finale on May 7. Here’s a statement from Executive Producers Carol Mendelsohn and Don McGill:
Paul made Capt. Brass a standout character. He is not just an original cast member, he is an original. In a show about forensics, fans always looked forward to the handcuffs coming out, and Capt. Brass putting his spin on the crime of the week, just as Paul Guilfoyle put his indelible stamp on the character and the show. He will be missed.
And some more detail in an article on the Hollywood Reporter site.