The childhood friend of a slain NBC executive has agreed to plead guilty to manslaughter in connection to what has been described as an accidental shooting death in March.

David Andrew Armstrong will face anywhere from probation to 14 years in prison when he's sentenced in November in connection with the shooting for NBCUniversal executive Brian Russell Kaplon.

Today, I am very pleased that he was able to plead to the appropriate charge of involuntary manslaughter. The defense has always contended this was an accident, said James Blatt, Armstrong's attorney, to CBS' KNX-1070 radio, from a courthouse in San Fernando, Calif.

Prosecutors said both 32-year-old men were drunk when the shooting occurred in the garage of Armstrong's home after a St. Patrick's Day party, where Armstrong was showing off a semiautomatic rifle.

Kaplon died from at least one shot to the chest, fired from an AR-15, a civilian version of the U.S. military's M16 semi-automatic rifle.

Nothing is going to bring Brian back, said Kaplon's widow, Kristi Kaplon. His children also miss him. My 3-year-old has separation issues . . . nothing they could ever do today will be justice enough for me.