ANN ARBOR, Mich. -- Police in Ann Arbor said they are looking for a group of four to 10 people who are responsible for the beating a 19-year-old University of Michigan student.

UM seniors Zachary Ward and Brian Barton said they saw the beating.

“He was getting kicked in the face, stomped in the ribs and legs and all over the gut,” Ward said. “A couple of guys around were just repeatedly punching him.”

Barton said the group started jumping on the victim’s car as he was driving down Elm Street on Halloween night at about 11 p.m.

The student was attempting to drive down the crowded street that was full of partygoers for the annual “Nightmare on Elm Street” block party.

Barton said he had his camera out and was snapping pictures for fun when he saw the beating and began recording it.

Barton said the victim accelerated, knocking the group from the car before getting out to confront them.

“Within seconds they were just on him,” he said.

Barton said he gave the memory card from his camera to police.

But a police representative said the card was lost when the officer who took the evidence put it in the same pocket as his notebook. The representative said the officer believes it fell out while he was interviewing other witnesses.

“I’d like to see some justice for this kid. People should not get away with what these kids did,” Ward said.

Police said they are still actively investigating the incident.

Anyone with information is asked to contact the Ann Arbor Police Department's tip line at 734-794-6939.