Four University of Pennsylvania students turned themselves in to Penn Police yesterday in connection with the alleged assault of a Princeton student on Nov. 16. A fifth student is expected to turn himself in today.
"We arrested four people. We have one more to go," said Frank Demeo, detective for the Penn Police.
The suspects' names cannot be released until they have been formally arraigned, Demeo said.
He said he expected the arraignment to occur late yesterday or today.
The charges against the individuals, who were all male undergraduates at Penn, range from criminal conspiracy to aggravated assault, Demeo said.
Demeo said it was his understanding that Princeton student John Brantl '05 intended to press charges after the incident, which occurred in a lounge in Penn's Quadrangle dormitory.
Brantl and other members of the Princeton Debate Panel were staying there during a tournament at Penn.
Brantl said he was sleeping when one of the suspects began harassing the Princeton students.
There was a verbal altercation, said Jeff Sandman, a Penn freshman who was housing the students.
Brantl, who could not be reached for comment yesterday, has said in previous interviews that he asked the individual to leave, but the person returned soon after with four others.
The suspects allegedly kicked him, threw motor oil on him and threatened to set him on fire, forcing him to promise never to return to Penn.
"The students surrendered to Penn Police at Penn Police headquarters at various times throughout the day," said Lori Doyle, vice president of communications at Penn.

"[They're] currently going through the Philadelphia arraignment process," she added.
The students will remain in the custody of Philadelphia police at least until arraignment, Demeo said. The time of the arraignment depends on the schedule of the Philadelphia police, he added.
The investigation will continue, Demeo said, and he could not rule out the possibility of more charges.
"We're still working with some aspects of the investigation," he said. "We'll see if there's any other merit to go in further with this."
Princeton officials expressed approval over the initial results of the investigation.
"We are pleased to learn that there has been progress in the investigation," said Lauren Robinson-Brown '85, communications director.