The revelation came one day after the same man, Larry Thompson, was indicted on a murder charge in a 1979 slaying in Shreveport, Louisiana.
Ocean County, New Jersey Prosecutor Joseph Coronato said Thompson cannot be tried again for the same crime, however -- the 1984 shooting death of Maria Marshall. Marshall was found shot to death in a picnic area along the Garden State Parkway.
Coronato said his office reopened the file on Thompson last year after hearing from the district attorney's office in Caddo Parish, Louisiana, because of similarities between the cases.
Marshall's husband, Toms River insurance salesman Robert Marshall, was convicted in 1986 of paying to have her killed, and for nearly 20 years was the first in line in New Jersey slated for execution after the state reinstated the death penalty in 1982. His death sentence was overturned in 2004 and the state abolished the death penalty three years later.
In a 2007 interview with The Associated Press, Marshall maintained that he is innocent and that he was framed. He remains in prison, but has a parole hearing scheduled for December.
The saga was the subject of Joe McGinniss' true-crime novel "Blind Faith" and a 1990 miniseries of the same name.
Thompson, who was accused of being the hit man, was cleared by the same jury that convicted Marshall.
The not-guilty verdict came largely because of an alibi. His wife, son, brother and others testified that Thompson took his son to a dentist in Louisiana the day Maria Marshall was killed, making it impossible for him to have been in New Jersey at the time.
Ocean County authorities said Thompson last month told James Churchill, a retired prosecutor's office detective who had worked on the case 30 years ago, that witnesses who said he was in Louisiana were lying or mistaken. Coronato said no one would be charged with lying to a jury because the statute of limitations for perjury is five years.
Thompson is a dozen years into an 80-year term for attempted murder of a police officer and armed robbery in Louisiana.
He now faces a murder charge for the 1979 death of Deana Montgomery. The alleged victim's husband, James Montgomery, was also charged with murder in the case. As in the Maria Marshall slaying, the victim was shot in the head at close range while in a car.
Authorities in both Louisiana and New Jersey said they did not know whether Thompson has a lawyer.
District Attorney Richard Johnson in DeSoto Parish, Louisiana, told the Shreveport Times authorities are also using information from the investigation to try to resolve the 1988 slaying there of Larry Lester. Thompson's son Brian was arrested in the case but never prosecuted.
Coke Solomon, the district attorney in Harrison County, Texas, said authorities are looking into whether Thompson might be connected to the unsolved 1979 slaying of Charles Underwood there.