By Jonathan Allen

NEW BRUNSWICK, New Jersey (Reuters) - The defense wrapped up its case on Monday in the gay bullying trial of a former Rutgers student accused of spying on a sexual encounter between his roommate, who later committed suicide, and another man.

Dharun Ravi, 20, told a judge that he would not testify in his own defense at the trial, which now moves to closing arguments on Tuesday.

"It's my decision, yes," Ravi told the judge after the ninth and final defense witness testified.

Ravi is charged with 15 counts of invasion of privacy, witness and evidence tampering and bias intimidation, which is a hate crime, in Middlesex County, New Jersey Court. If convicted, he faces 10 years in prison.

His freshman roommate, Tyler Clementi, 18, jumped off the George Washington Bridge on September 22, 2010 after learning Ravi, using a webcam, covertly saw him kissing another man and appeared to encourage others to watch.

Ravi is not charged in Clementi's death, which drew national attention after it was widely portrayed as a consequence of bullying.

Prosecutors accuse Ravi of intimidating Clementi and spying on him because he was gay. Ravi's lawyer says it was simply childish behavior by an immature first year college student, but not criminal.

Among the nine defense witnesses to testify were seven character witnesses who said they never heard Ravi make a disparaging remark about gays, an investigator from the prosecutor's office and a detective from campus police.

One of the last people to see Clementi alive, the other man in the sexual encounter who said they met through an online gay social network, was among two dozen witnesses to testify for the prosecution.

(Editing By Barbara Goldberg and Paul Thomasch)