Is this the sign that “CSI: Crime Scene Investigation” is jumping the shark?

Adolescent heartthrob Justin Bieber will be the featured guest star in the Sept. 23 season premiere of the CBS crime drama.

Bieber will play a troubled teen,who has to make a decision involving his only brother that casts him into a confrontation with the investigative team.

The situation will not be resolved until later in the season, according to CBS, which didn’t reveal whether this would entail a return visit by Bieber.

If nothing else, Bieber’s appearance will bring down the aging demographics of the series for at least one week. The hope, of course, is that some of the younger people who tune in will become regulars.

Doubtful.