Superior Court Judge Glenn Berman also ruled that no part of a 15-count indictment of Clementi's former roommate, Dharun Ravi, will be dismissed. In doing so, he denied Ravi's lawyer's contention that prosecutors did not offer a grand jury earlier this year enough evidence about the alleged crimes.
Ravi is accused of the hate crime of bias intimidation, using a webcam to invade the privacy of the two men and trying to cover up it up afterward.
Days after the alleged spying in September 2010, the 18-year-old Clementi committed suicide by jumping off the George Washington Bridge. His story set off a national conversation about bullying of young gays.
While the judge said defense lawyers had the right to the name of the other man in the encounter, it came with catches. They cannot reveal the name of the man, identified in court documents as M.B., to anyone except for their investigator and Ravi. And they're not allowed to tell anyone who he is.
Berman also said that they can attempt to interview the man only at the office of the Middlesex County prosecutor and with a representative from the office present. And, he warned, M.B. has the right to decide not to talk with Ravi's lawyers at all - and predicted he will decide to exercise that right.
Ravi sat between his lawyers wearing a charcoal suit, and mostly kept his eyes trained on the judge. He did smile at one point about some confusion over the man's initials.
Who M.B. is and what he knew has been one of the persistent mysteries of a case that has unfolded publicly over the last year.
Court documents suggest that Ravi and some other Rutgers students glimpsed him briefly in an encounter with Clementi on Sept. 19, 2010. Ravi is also accused of setting up his webcam to try to capture them in a second liaison two days later. Ravi has denied all charges.
Steven Altman, a lawyer for Ravi, said, the man may be able to shed light on whether Clementi felt his roommate was intimidating him because he was gay.
"I'm not seeking any of this information to embarrass or humiliate anybody," Altman told Berman. "All I want to do is learn as much as I can as an attorney to represent Dharun Ravi. The prosectuor's office can't pick and choose what to give me under the guise of victim's rights."
Prosecutors argued that there could be harm done to M.B. by telling the defense his name, and said it had already provided two statements from him to Ravi's lawyers.
Invasion of privacy is classified as a sex crime, Assistant Prosecutor Julia McClure argued, and state law requires that details about sex-crime victims not be disclosed.
Berman said the intent of those protections didn't fit here: "I can't conclude that MB is a potential victim" of additional intimidation, he said.
Defense lawyers had also sought other evidence that Assistant Middlesex County Prosecutor Julia McClure said was irrelevant: reports from the Port Authority of New York and New Jersey Police Department, which patrols the George Washington Bridge; records from Clementi's computer and some of his hand-written notes.
Berman said he would review those items in his chambers before deciding whether they're pertinent to the case and should be given to the defense.
He said the prosecutor should not decide which evidence might be relevant in the case. McClure said her office could appeal parts of Berman's ruling.
A hearing was set for Oct. 20 to set a trial date.