Opening statements were heard Wednesday in the trial of a Rockville Centre police officer accused of assaulting two brothers outside a bar in May 2016. 

Cellphone video of the incident shows the altercation with brothers Kevin Kavanagh, 27, and Brendan Kavanagh, 21, both of Rockville Centre, and Officer Anthony Federico.  

Federico had responded to a call about a late night fight involving the brothers with some other men outside several bars on South Park Avenue. 

During opening statements, prosecutors told the judge that Federico used excessive force by using his Taser on the brothers. They say he also smashed the Taser into Kevin Kavanagh's head.

Federico's attorney William Petrillo said that the cellphone video shows that his client was the one under attack. 

"This is a great police officer. The evidence is going to show he acted appropriately and professionally in a most-dangerous situation," says attorney William Petrillo. 

The judge heard from the woman who recorded the cellphone video, Alyson Gallo, who is friends with the Kavanagh brothers. She broke down in tears on the stand as she described the scene. 

She said Federico beat and punched Kevin. She said her friend's face was like "something out of a horror film."

She also said she chose to record the incident because she thought Federico was aggressive from the moment he responded. 

"I didn't think he was there to help us. I didn't think he cared...with the demeanor he had," she said. 

The Kavanagh brothers and Gallo were initially arrested and charged with assaulting the officer. Those charges were eventually dropped.

Federico faces up to seven years if convicted.