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Ten Muslim students broke the law by shouting down a speech by an Israeli diplomat at the University of California, Irvine, in a carefully drafted and executed plan that flouted repeated warnings by campus officials, a prosecutor said Monday.

In closing arguments at the trial that stoked fierce debate about free speech, prosecutor Dan Wagner told jurors that emails among the students revealed they knew they could be arrested when they got up, one by one, and shouted pre-scripted statements to interrupt Israeli Ambassador Michael Oren's talk on U.S.-Israel relations in February 2010.

"The right to free speech is not absolute," Wagner said before a packed courtroom of more than 180 people in Orange County, with more observers waiting outside. "If hecklers' vetoes were allowed, then nobody, nobody, none of us would have the right to free speech."

Defense attorneys were expected to argue later in the day on behalf of the students, who face misdemeanor charges of conspiring to disrupt a meeting and disrupting a meeting. If convicted, the students — many who have now graduated from UC Irvine and nearby University of California, Riverside — could face sentences ranging from probation with community service and fines to a year in jail.

The case also raised questions about prosecutorial discretion, with some members of the public calling the trial a waste of taxpayers' money. Other community members have said the defendants were being singled out because they are Muslim.

Wagner said students acted as censors to block the free flow of ideas and infringed on the rights of 700 people who had gone to the suburban campus that evening to hear Oren.

The interruptions — combined with cheering from supporters, admonishments from university officials trying to regain control, and a forced break in the meeting — absorbed more than half the event, he said. A question and answer period where dissenters could have challenged Oren was cancelled because of limited time, Wagner said.

Defense attorneys have argued that Oren was able to finish his talk after students and their supporters walked out, and that the students' remarks, including phrases such as "propagating murder is not an expression of free speech," accounted for less than five minutes of his time.

Some community members have also said the aftermath of the demonstration should have been handled exclusively by the university.

The students were initially cited, released and disciplined at UC Irvine, which revoked the Muslim Student Union's charter for a quarter and placed it on two years of probation.

Nearly a year later, Orange County District Attorney Tony Rackauckas filed criminal charges against 11 students. The move prompted an outcry from the American Civil Liberties Union and a host of Jewish, Muslim and campus groups.

The filing also sparked a media frenzy, and Superior Court Judge Peter J. Wilson eventually issued a gag order to prevent prosecutors and defense attorneys from arguing the case outside the courtroom. The charges against one defendant were later dropped.

On Monday, Wagner showed video clips of university officials pleading with demonstrators to behave and respect academic freedom. He also showed numerous emails among members of the Muslim Student Union planning the disruption and calculating who was willing to get arrested.

The correspondence, Wagner said, reveals students knew the risk of their actions and later tried to cover up that the organization was involved in the protest.

"It was always a plan to break the rules," he said.