A Camden man who served just six years in prison for killing a man will now rot behind bars after killing a witness who testified in his previous manslaughter trial.

Richard Santiago, 63, was sentenced this week to 60 years in prison for stabbing to death 54-year-old Ramona Johnstone in 2012.

Johnstone had been a prosecution witness in Santiago's 2006 trial for the slaying of 44-year-old Richard King, of Mantua. Santiago had been convicted of aggravated manslaughter in King's killing and was sentenced nine years in prison.

Seven months after he was released from prison on May 6, 2012, he went after Johnstone, who was found by authorities unconscious in her Woodbury Court apartment and later pronounced dead at Underwood-Memorial Hospital.

A later autopsy concluded that she died of multiple stab wounds. The knife used to stab Johnstone multiple times was never found, according to the Gloucester County Prosecutor's Office.

Santiago's motive for murdering Johnstone, who was friends with King, was revenge for his conviction in the death of King, Gloucester County Prosecutor Office's Senior Assistant Prosecutor Laurie Cimino told the jury on Friday.

Santiago was convicted  May 24 of first-degree murder in Johnstone's death and third-degree hindering prosecution. Santiago received a 60 year term in prison — double the mandatory 30-year murder sentence.

Superior Court Judge Christine Allen-Jackson said she handed down the 60-year sentencing due to the high risk of Santiago committing another crime.

Santiago must serve 51 years of the sentence before he can be paroled. He would be 114 years old.