Watch: How father and son were shot dead after argument with neighbor in U.S

A father and son were allegedly shot dead by their downstairs neighbor in Brooklyn Sunday night.  The search is still on for the shooter.

The victim's family called the suspect psychotic, saying he would constantly complain about noise when they weren't making any. On Sunday, they say he confronted the family yet again, this time pulling out a gun.

"He killed my brother and my dad," the victim's daughter said.  His family in East Flatbush, Brooklyn is shattered after police said the disgruntled neighbor opened fire Sunday night, killing 47-year-old Bladimy Mathurin and his 27-year-old son, Chinwai Mode.

"This man hates us with every bone in his body," Mathurin's wife Marie Delille said. She's now a grieving widow, and mother.

She said ever since her family moved onto the fourth floor of the Flatbush Gardens apartment building four years ago, they've butted heads with the man living directly below them complaining that their children are being too loud.

Sunday was no exception.

"I was in the kitchen, doing dishes in the sink, I heard bang bang bang. I asked did anybody make noise? The kids be like, no mommy, nobody made noise. My husband banged back. The man came upstairs and kicked the door," Delille said.

According to police, Mathurin opened the door, argued with the neighbor, and was threatening him with a pair of scissors when the suspect opened fire, shooting the father and his son in the head. But Delille, who says she was present, maintains the police have it all wrong.

"My husband had no gun, no weapon. Why did you bring a gun to shoot my family? Why would you bring a gun to tear my family apart? Why? Why?" Delille said.

"He's a muscular guy. He looks intimidating, but that's not who he is. He is a wonderful guy," family friend Mickael Louis said.

Family and friends say, while grieving this tremendous loss, they are also worried about their safety, afraid the shooter could return anytime.

"I need justice to be served," Delille said.

Watch the shooting below: (GRAPHIC content)