The illegal arsenal was found at 24-38 West Street in the Gravesend section. Four people are now sitting behind bars.
There were more than two dozen unregistered weapons in all, and authorities say they belonged to a family of three and a 29-year-old man who lived with them.
"Sure I'm concerned," neighbor Pat Mylone said. "But I had no knowledge anything like this took place here."
The illegal stockpile was confiscated from a two-story home on West Street Friday afternoon, when police executed a search warrant after being tipped off.
The search got the attention of the neighborhood, especially since it happened across the street from a grade school.
"That's the most I've ever saw, like so many fire trucks and ambulances on this block," neighbor Priscilla Consolo said.
Police arrested 57-year-old Thomas Siano, 58-year-old Kathleen Siano and their son, 29-year-old Vincent Siano. Also arrested was 29-year-old Michael Poole.
It's not clear to investigators how long the family has had the guns or why they were never properly registered.
But the Siano's friends say police have it all wrong.
"Vinny's a harmless person," family friend Christina Ortega said. "I grew up with him. He's actually one of my best friends. Everything was passed down through family or they are collectibles."
Meanwhile, Poole's friends say he just rents the apartment downstairs from the family, and had no idea what was going on.