The standoff, which began around 12:30 p.m., ended almost 8 hours later.
Several rounds of tear gas had been shot into the home before police made their way into the Versailles Apartments on the 200 block of Sullivan Way in Ewing Township Thursday night.
Once inside, New Jersey State Police say they located the suspected shooter, 50-year-old Wayne Voorhees, who was suffering from a self-inflicted gunshot wound to the head.
He was transported to Capital Health Regional Medical Center alive, but his condition is otherwise uknown.
The lone victim, 24-year-old Timothy Rivella of Ewing, was found lying on a parking lot of the apartment complex.
Officers first noticed Rivella upon arrival, but were unable to move closer to him due to the proximity of the shooter.
Investigators do not know if the shooting was random or if Rivella was targeted.
Voorhees reportedly shot at law enforcement personnel when they first responded to the scene.
Shots were also heard around 7:00 p.m. But no other injuries were reported.
Earlier, police tried to make contact with Voorhees; they brought in negotiators and his family to try and facilitate a surrender. However, police never talked with the suspect throughout the standoff.
As the standoff began, residents were told to stay inside and away from windows. Once deemed safe, authorities evacuated the immediate area.
Other nearby homes and businesses were locked down, as well.
After the standoff ended, all residents were allowed back in their apartments.
The Associated Press contributed to this report.