New Jersey leaders mourn councilman killed in workplace shooting

New Jersey leaders are mourning the loss of a councilman who was killed in what police said was a targeted workplace shooting on Wednesday.

Russell Heller was fatally shot outside utility company PSE&G's Somerset Central Division Headquarters in Franklin Township, where he was the senior distribution supervisor, officials said.

Heller, 51, was also a councilman in Milford, a small borough in Hunterdon County.

"The Milford Borough Council is deeply saddened by the loss and our hearts go out to his family," Milford Mayor Henri Schepens said in a statement. "He was so full of life, it's just unbelievable that he's gone. Something like this has never happened in borough history. We are very shaken by this."

Heller, a Republican, was first elected to the Milford Borough Council in 2017 and re-elected in 2020.

"Our thoughts and prayers are with Russell Heller's family and friends in the wake of this tragic act of gun violence," New Jersey Gov. Phil Murphy tweeted.

Franklin Township police responded to multiple 911 calls reporting a shooting victim in the parking lot of the PSE&G location around 7 a.m. Wednesday, the department said. Heller was found dead from a gunshot wound, police said.

Investigators determined that a former PSE&G employee -- identified as Gary Curtis, 58, of Washington, New Jersey -- allegedly approached Heller in the parking lot and shot him while he was outside his vehicle, police said.

Curtis was tracked to a parking lot in Bridgewater Township, New Jersey, within an hour of the shooting, according to police. As law enforcement officers approached they "observed him suffering from a self-inflicted gunshot wound" and he was pronounced dead at the scene, police said. A handgun revolver recovered from the scene was legally registered to Curtis, according to the Somerset County Prosecutor's Office.

The Somerset County Prosecutor's Office along with Franklin Township Police are investigating the homicide.

The alleged motive was determined to be "prior employment disciplinary actions between subordinate and supervisor," the Somerset County Prosecutor's Office said in an update on Friday.

"The investigation has revealed that the shooting was an isolated incident and Mr. Heller was the intended target," the prosecutor's office said.

Investigators determined that the shooting was not connected with Heller's "elected office or political affiliation," Deputy Chief Frank Roman Jr. with the Somerset County Prosecutor's Office said in a statement Thursday.

PSE&G said it was "heartbroken" over the death of Heller, who had been a supervisor with the company for over 11 years.

"This event is tragic and disturbing, and we are offering support to our employees as they process this," PSE&G said in a statement.

New Jersey Congressman Tom Kean said he was "shocked and saddened by the tragic murder" of Heller.

"Russell was an outstanding public servant who proudly represented the river town he loved," Kean tweeted.

The incident comes one week after the separate, fatal shooting of another New Jersey council member.

Sayreville councilwoman Eunice Dwumfour was shot and killed on Feb. 1 while sitting inside her SUV outside her home, police said.

Dwumfour sustained multiple gunshot wounds in her SUV and was pronounced dead at the scene, according to police.

Dwumfour -- the mother of a 12-year-old daughter and leader of her church -- was elected into office in 2021 and worked as a business analyst and part-time emergency medical technician.

No arrests have been announced in the case.

ABC News' Nadine El-Bawab contributed to this report.