BELLPORT - Police say a member of Long Island's famous Grucci fireworks family has been arrested for shooting his 20-year-old grandson during a dispute early this morning. Police responded to a home on Wards Lane in Bellport after a 911 caller reported a dispute and possible gunshots being fired at 3 a.m. Cops say when they arrived, 70-year-old Joseph Grucci told officers he got into a heated argument with his grandson, Christopher Giresi, because he claimed the 20-year-old and his friends were making too much noise in the house.During the dispute, detectives say Giresi pushed his grandfather, trashed the house and threatened to kill him if he called police, prompting Grucci to fire twice at Giresi with a 20-gauge shotgun. "His grandson lunged toward him, he said that's when he felt the need to shoot him," says Detective Sgt. Daniel Molloy, of the Suffolk County Police Department.Giresi was transported to Brookhaven Memorial Hospital with injuries to his torso and arm. He is listed in stable condition. Police say Giresi had been living with Grucci for 10 years. He is currently out on bail on drug possession charges.Grucci has been charged with assault in the first degree. He is being held on $500,000 cash bail. Grucci also has been issued a stay away order, which means that should he post bail, he will be able to return to his house only once with police escort to gather some of his belongings and then find another place to live.