Spoiler Warning: The content includes plot and ending details for CSI: Crime Scene Investigation.

CSI: Crime Scene Investigation, simply known as CSI, has been a fan favorite for a very long time.

As the show's name goes, it revolves around a group of crime-scene investigators who solve crimes, especially murders, using physical evidence.

The series was on air on CBS from October 6, 2000, to September 27, 2015. It has 337 episodes spanning 15 seasons.

It starred acclaimed actors like Ted Danson, William Petersen, Marg Helgenberger, Jorja Fox, George Eads, Laurence Fishburne, and Gary Dourdan.

Throughout the 15 seasons, CSI saw a lot of changes in the cast which disappointed many fans and followers. But arguably, Dourdan leaving the show prematurely was one instance that hurt the fans the most.

As a result, many started questioning, "Why did Gary Dourdan leave CSI?" The answer is more simple than you think it is.

Warrick Brown's Death in 'CSI'

Dourdan played the role of Warrick Brown; a recovering gambling addict turned audio-video analyst for the investigation team. He was a vital part of the team and helped them solve cases many times.

He was one of the main cast of the investigation series until his character was killed off at the end of Season 8. Brown was falsely accused of murder but later acquitted at the end of the eighth season.

Unfortunately, he was shot in the car during the finale. At the premiere of Season 9, it was revealed that he died in the arms of his teammate, Gil Grissom (portrayed by Petersen).

Thus, Brown's death confirmed that Dourdan would not return to CSI.

Why did Gary Dourdan leave CSI?

On April 14, 2008, it was reported by TV Guide that Dourdan would not return to the show for the ninth season. The announcement was made before Brown's death in Season 8.

This made many speculate that the actor was leaving because of his arrest in 2008 on drug possession. He was found asleep in a car parked on the wrong side of the road.

When the police officers approached Dourdan, he looked "disoriented and possibly under the influence of alcohol and/or drugs." He was then arrested and released on $5000 bail.

Gary Dourdan left 'CSI: Crime Scene Investigation' after his contract ended in 2008. (Source: Instagram)

However, later it was confirmed that the reason behind him leaving CSI was not because of the arrest. Dourdan did not reveal why he was exiting the series and did not make any comments about his character's death.

The real reason he left the show was that his contract had ended. Allegedly, the negotiations fell through, and Dourdan and the production company did not reach the middle ground.

Entertainment Weekly reported an insider told them the decision to leave was mutual between him and CBS/Paramount. They also claimed that Dourdan might reprise his role as a guest star in the future.

Since he was one of the few African-American men in the leading role, there were high chances that the actor might occasionally appear in the upcoming seasons.

But since his character was killed off, the chances of him returning were omitted. As a result, he never returned to CSI.