Mr. Bergrin said that Sergeant Feder had never received complaints from any comedy club patrons. He said he suspected that the CD was sent to police officials as an act of retaliation by a rogue police officer Sergeant Feder had investigated. "It's hard to imagine who else might do such a thing," he said.

Police officials say they are still not sure who sent the CD. But once they heard Sergeant Feder onstage delivering punch lines about raping a bride at knifepoint, having sex with his dog and sexually molesting his own 5-year-old son, they opened an investigation that led to several departmental charges, they said. The department alleges that he used a police computer to write one of the controversial monologues. It has also charged that he violated the regulation requiring officers to notify their superiors about moonlighting.

But Mr. Bergrin said that Sergeant Feder's performances did not qualify as moonlighting because he was not paid for them and, even if he had been, police supervisors were notified about his work onstage.

As for the primary charge -- that Sergeant Feder violated the department's moral turpitude clause -- his supporters say that obscenity is in the eye of the beholder. The West Orange Police Department's uniform standards of conduct prohibit any "deeds, signs or actions that violate public morals or the common sense of the community."

But Jamie Masada, who owns the Manhattan comedy club where Sergeant Feder gave the performance that landed him in trouble, said that the public was clearly sophisticated enough to recognize when comedians are trying to wield offensiveness as an art form.

"Howard Stern has made $500 million talking about sex with midgets," said Mr. Masada, who founded the Laugh Factory comedy club. "So people obviously find it to be entertaining. That's what entertainers do -- talk about things that the public finds funny."

But Chief Abbott's opinion on the matter is likely to offend even Sergeant Feder. He thinks his sergeant's routine is outdated rather than amusing.

"Back in the '80s, when Andrew Dice Clay and all these shock comics were coming up, it was funny because it was shocking," he said. "You couldn't believe they were actually saying all these things. But now they've said it all already, so it's not shocking or funny. And no one wants to hear it from a police officer."