Second US politician shot dead in a car in space of one week - community in shock
Police insist the two incidents are not linked and the FBI is searching for Ms Dwumfour's killer, who is on the loose and unidentified.
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It happened exactly seven days after fellow local Grand Old Party official, Eunice Dwumfour, was shot dead in a vehicle outside her home - a short drive away.
Police are insisting the two incidents are not linked and the FBI is searching for Ms Dwumfour's killer, who is on the loose and unidentified.
The horrific killings have shocked the communities of Somerset County in New Jersey - an area with a population of around 340,000 on the outer edge of New York.
Gary Curtis, 58, has been identified as the suspect in Mr Heller's death. He was found dead with a gunshot wound in what officers believe was a suicide.
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In a statement, Somerset County Prosecutor's Office said: "The investigation remains ongoing to determine motive."
Express.co.uk has approached the prosecutor for further comment.
Mr Heller, a councilman, was killed in Milford - 15 miles from Sayreville where councilwoman Ms Dwumfour was killed.
New Jersey's Democratic Governor Phil Murphy sent his "thoughts and prayers" to his family and friends "in the wake of this tragic act of gun violence".
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Republican Representative Tom Kean Junior, whose district includes the area, said he was “shocked and saddened by the tragic murder”.
He added: "Russell was an outstanding public servant who proudly represented the river town he loved."
The local community in Milford also appeared stunned by Mr Heller's death.
Mayor Henri Schepens told NJ.com: "Milford Borough Council is deeply saddened by the loss and our hearts go out to his family."
He continued: "Something like this has never happened in borough history. We are very shaken by this."
Ms Dwumfour was shot at around 7.20pm last Wednesday outside her apartment in Parlin.
Her car then rolled down the street and crashed into parked cars at the base of the hill.
Friends and family of the 30-year-old gathered yesterday to remember her.
No arrests have yet been made in connection with Ms Dwumfour's death.
However, Middlesex County prosecutor Yolanda Ciccone revealed that the FBI is helping investigators conduct scientific analysis.