The reward for information leading to the killer of a Rowan University sophomore was doubled yesterday to $100,000, the highest such bounty ever offered in Gloucester County, authorities said.

The additional $50,000 was contributed by the university in the hope it might tempt someone who knows the killer to come forward, Rowan president Donald J. Farish said.

Donald Farrell, 19, of Boonton Township, Morris County, was walking with friends to a Glassboro convenience store near campus on the night of Oct. 27 when he stopped to give directions to a group of five men.

Without provocation, a member of the group punched Farrell in the neck. After Farrell collapsed to the ground, another man kicked the business major. One of the two men then rifled through Farrell's pockets, taking a cell phone and wallet, investigators said.

The attack happened so quickly that Farrell's four companions could do nothing to save him, investigators said.

The assailants drove away with the other men in their group. Farrell died the next day of a ruptured blood vessel.

Tips have flooded the Gloucester County Prosecutor's Office since the attack, officials said. Sixteen detectives working on the case have traveled to New York, Pennsylvania, Delaware and throughout New Jersey investigating leads, Prosecutor Sean F. Dalton said.

"We want to bring Donnie Farrell's family some closure," Dalton said. "If the assailant's friends come forward, they can be the heroes in this case."

Images of the man believed to have beaten Farrell were caught by a surveillance camera at the nearby XPress Mart convenience store shortly before the attack.

In the video, he is seen buying a pack of cigarettes and a Dutch Masters cigar. The man is wearing a sweatshirt identified as a Coogi Heritage hoodie, with a gray body, red sleeves, and a British flag logo on the left chest area.

The suspect, who also wore a New York Yankees baseball cap, is black, in his 20s, about 5-foot-7, with a medium complexion, braided hair, a thin moustache and a light goatee.

A tattered memorial to Farrell remains near the site of the killing, about 20 yards behind the convenience store alongside a campus access road. Yesterday, hundreds of carnations lay wilted around a small weathered cross and an orange T-shirt emblazoned with "Rowan United."

Farish said that since the attack the university has hired additional security officers, increased lighting, installed new emergency phones, and beefed up its student-escort service.

The school had "no prior experience with this kind of brutal activity," he said. But he acknowledged that Farrell's jaw was broken in a fight with a student at an off-campus party earlier this year.

Farrell filed charges against the student and made a statement to a school disciplinary board, Farish said. The charges have not been resolved.

"It is highly unusual for two incidents to have occurred to the same student back-to-back," Farish said. "It was a coincidence. As far as we know, the night he was killed he was doing absolutely nothing wrong.

"There's no evidence that Farrell was drinking," Farish said. "He was simply in the wrong place at the wrong time."

Anyone with information is asked to contact investigators at 856-307-7180 or mcu@co.gloucester.nj.us.

To see video of Donald Farrell's suspected assailant, go to http://go.philly.com/farrellEndText

Contact staff writer Sam Wood at 856-779-3838 or swood@phillynews.com.