BOSTON -- A Boston EMT is accused of shooting his late work partner's brothers outside a house party this weekend.

Rhys Williams, 41, of Dorchester, allegedly shot John Brinkman, 42, of Quincy, and Paul Brinkman, 36, of Hanover, on Sunday morning in Abington.

After the shooting, Williams called 911 and then tried to give medical attention to the victims.

"After the shots were fired, he grabbed his EMS bag. The people had come out of the house -- the wives -- and was attempting assist the victims he had just shot and render some type of first-responder (help)," a police official said.

The victims' brother, Mark Brinkman, who died in May, once worked with Williams.

John Brinkman and Paul Brinkman confronted Williams after he was asked to leave the party, according to police.

"Two shots were fired. The first one strikes John Brinkman in the leg. The second is pointblank to the chest area right below the sternum to Paul Brinkman and strikes him in the chest," the official said.

John Brinkman was treated at South Shore Hospital and released, but his brother remained in poor condition at a Boston hospital, officials said.

"I am not sure what his motive was," the official said.

Williams was charged with two counts of attempted murder and assault and battery with a dangerous weapon. He was held without bail and was placed on administrative leave from Boston EMS.