The results of the case, dubbed "Operation Zombie," were announced during a news conference on Monday in Camden with the attorneys general of New Jersey and Pennsylvania.
The operation was conducted by the Department of Justice, the FBI, along with state and local police.
The sting resulted in the recovery of 36 guns and 20 ounces of methamphetamine, officials said.
It's just too easy for criminals to buy guns in other states with weaker laws & funnel them into NJ.— AG Gurbir Grewal (@NewJerseyOAG) January 27, 2020
That's why @PAAttorneyGen & I are launching the PA/NJ Gun Trafficking Initiative - to better tackle the iron pipeline of illegal firearms, solve gun crimes, & protect residents. pic.twitter.com/EiJjcHTv4Q
Several of the guns had been used in crimes, including the killing of 2-year-old Nikolette Rivera.
The girl was struck by a bullet fired from an assault rifle outside her home last fall. The child died in her mother's arms at the scene.
"Although two men were charged in Nikolette's murder, the gun used in the shooting was not recovered until last month. It was recovered when a Philadelphia gun trafficking named Robert Crosley allegedly sold it to a buyer here in Camden," said New Jersey Attorney General Gurbir Grewal.
Police say many of the guns were obtained by illegally paying "straw purchasers" to buy guns in Pennsylvania at dealerships and gun shows.
The multi-agency investigation is ongoing, including looking into those involved in straw purchases.