Mercer County Prosecutor Joseph L. Bocchini Jr. says 50-year-old Wayne Voorhees shot 24-year-old Timothy Rivella before holding police at bay for nearly eight hours from inside the Versailles Apartment Complex in Ewing on Thursday.
Both men lived at the Versailles Apartments and investigators say the shooting incident appears to stem from a dispute over a parking space.
Acting State Police Capt. Frank Davis says the standoff ended after state police stormed the unit and found Voorhees with what appeared to be a self-inflicted gunshot wound to the head.
He was last reported to be in serious condition and is expected to survive.
Police were unable to retrieve Rivella's body until the standoff ended. An autopsy is planned for Friday.
The prosecutor's office said it searched Voorhees' apartment and found four weapons (three shotguns and a rifle) plus hundreds of rounds of ammunition.
Bail for Wayne Voorhees has been set at $1 million.