John Patterson tried to end an argument at a Goodale Road party Sunday morning by pulling a knife on his opponent, but after people wrested the weapon away, he went outside, got a gun, shot Jeudy Romero to death, then grabbed Romero's keys and drove away in his car, a Suffolk County prosecutor charged Monday.

Patterson, 29, of Peabody, was ordered held without bail at his arraignment Monday morning in Dorchester District Court on a charge of murder for the death of Romero, also 29, who leaves behind four young children and who was a US Army veteran.

As both Romero's and Patterson's families listened, on opposite sides of the courtroom, Assistant Suffolk County District Attorney Jennifer Hickman said Patterson got into an argument at the party around 9:30 a.m. After people wrested away the knife, he left, but then returned a couple minutes later with a gun, she said. "Let me show you who I am!" he told people, then fired and hit Romero with a fatal shot, Hickman said.

Hickman said officers spotted Patterson in Romero's car near Blue Hill Avenue and managed to get him to stop. But as an officer approached the driver's side - with gun drawn - Patterson sped off, she said. Officers found the car on Fuller Street near Codman Square, then found Patterson on foot on Washington Street, where they arrested him, she said.

In addition to murder, Patterson was charged with various gun offenses and with receiving stolen property - Romero's car.

Hickman said that Patterson has a record that includes a rape conviction in Essex County.