sean-montgomery-rbrRed Bank police have charged two recent Red Bank Regional High graduates and a third man in the vicious attack that left a classmate with injuries last month.

Police identified Sean Montgomery, left, of Little Silver and Shrewsbury, as the instigator of  the June 19 beating at a party on Spring Street that left Julliard dance scholar Anthony Tiedeman with a broken jaw that required surgery.

Montgomery, 18, turned himself in last week after police issued a complaint charging him with aggravated assault, said Captain Darren McConnell.

Another classmate, Perry Campanella, whose town of residence McConnell did not have immediately available, and Jahmer Bunch, of Neptune, are expected to appear for arraignment in borough court with Montgomery on Thursday. They, too, are charged with aggravated assault. Each is 18 or 19 years old, McConnell said.

Tiedeman, Montgomery and Campanella were members of the class of 2011, which graduated just two days prior to the party at which McConnell said Tiedeman was attacked.

A longstanding dispute over a girl led to the attack, McConnell said.

“It sounds like it was just kind of a high school beef,” he said. “There doesn’t seem to be anything more to it than that.”

Tiedeman, he said, was attacked by the trio without provocation.

“Sean Montgomery seems to be the one who had the problem with him,” McConnell said. “The other two were just sort of there as friends of his.”

Police, summoned to the scene at about 10:30 p.m. that Sunday night, found Tiedeman bleeding and bruised. He was briefly hospitalized for surgery on his jaw, McConnell said.

McConnell said Tiedeman was able to immediately identify his assailants to police, but the process of finding other potential witnesses among the “dozens” of party attendees and interviewing them caused a delay in issuing charges.

Police explored the possibility of a bias attack, but ruled it out because “Tiedeman is not a member of any protected group that the bias statute applies to, and the attack appears to have been motivated by just a general dislike” of the victim.