Police went to the Paragon apartment complex in Jackson, Ocean County around 11 a.m. Saturday, after receiving reports of shots fired.
They soon found Toraya Reid, 28, unresponsive near the complex's exit, and she apparently had been shot multiple times, Ocean County Prosecutor Bradley Billhimer said.
Officers also saw Shaquille Green, 29, of Jackson running down a nearby road, and he was soon taken into custody without incident.
Besides the murder count, Green also faces two weapons charges. Billhimer said Reid and Green had been in "a dating relationship" but did not provide further details.
Green remained jailed on Monday, and prosecutors did not know if he had retained an attorney.
Reid, 25, a New Jersey native and a star scholastic player in his home state, is about to enter his seventh season with Minnesota and recently signed a five-year contract with the team. He was named the NBA's "Sixth Man of the Year" for the 2023-2024 season.
Reid's agents did not immediately respond to an email seeking comment on Monday.