Trial began today for two Prince George's police officers accused of beating a University of Maryland student during a melee that followed a March, 2010 basketball game between the University of Maryland and Duke University.

Officers Reginald Baker and James Harrison are both accused of first and second degree assualt and police misconduct for beating student John J. McKenna with batons during the melee the night of March 3 and the early morning of March 4. The alleged beating was captured on video, which has become a key piece of evidence in the trial.

Former Maryland student Nathan Cole testified that he was 10 feet from fellow student McKenna when he saw police with shields and batons strike McKenna over and over again. "I'll tell you I lost several days sleep over it. I really did. It really really bothered me."

The officers "abused their power, broke trust, and violated the law," said prosecutor Joseph Ruddy during his opening statement. "For that abuse they must be held responsible."

McKenna said he suffered a concussion and other injuries in the incident. Police ultimately arrested 23 students after the Maryland-Duke game.

Attorneys defending the officers said police commanders had ordered that officers use riot shields and batons, and ordered "zero tolerance for people who broke the law" that night. They pointed out that police were so concerned about the possibility of a riot that they were rooting against the Maryland team. The defense said McKenna was waving his fists as he approached the police line and tried to throw a punch.

"Was this a celebration or a riot?" asked defense attorney William Brennan, who represents Baker. He noted that the civil disturbance unit was called out that night, "not the civil celebration unit."

Baker and Harrison were charged following a federal investigation.