OAKLAND, Calif. (KRON) — The Oakland Police Department seized at least 20 ghost guns from a home on Tuesday, it announced in a press release. Officers were originally called to the location for the report of a “negligent discharge of a firearm.”

OPD responded to the 3000 block of Broadmoor View, which is near the Oakland Zoo, just before 7:45 p.m. As officers arrived, they heard more gunshots.

Officers searched the area and saw someone leaving a nearby home wearing body armor. They found a bullet casing in the driveway and detained the person.

A search of the area found that no nearby residences were struck by gunfire. Police searched the residence on Broadmoor View and found no people inside but plenty of weapons.

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At least 20 ghost guns were found, along with materials used to make the ghost guns. Images from OPD (below) show some of the recovered firearms have unique designs, including one with a dragon design around its muzzle.

The suspect, who police did not name, was arrested for firearm-related charges and for the negligent discharge of a firearm.