LOS ANGELES — A group of 100 faculty members at UC Irvine signed a letter asking the Orange County, Calif., district attorney to drop criminal charges against 11 Muslim students who disrupted a speech by the Israeli ambassador to the United States.

The group, including five deans, said the Muslim Student Union was wrong to disrupt the speech last year by Ambassador Michael Oren but that the students and the group had already been disciplined by the university.

Orange County prosecutors announced last week they were charging the students with two misdemeanor counts, including conspiracy to disrupt the speech. If convicted, each faces up to six months in jail.

The decision to charge the students, the faculty letter says, “”sets a dangerous precedent for the use of the criminal law against nonviolent protests on campus.””

“”I think there was a great deal of dismay that the DA was reviving what we thought had been a closed chapter in the university’s history,”” said UC Irvine history professor Jon Wiener.

The district attorney has argued that the students organized to squelch the speaker in clear violation of the law. The students are set to be arraigned March 11 in Santa Ana.