Mane, who admitted ordering the hit, was released last year. Manihera was released this year and Maru - who police say was the shooter - has waived his right to parole until September next year. Luke will go before the board next month.
Despite two decades passing since he died, his family are still struggling with the loss of Mr Crean.
His mother, Liz, lives in Opunake with her younger son, Robert. Their well-kept home is dotted with family pictures, including a striking photo of Chris holding his Bible.
Mr Crean's father, Mike, died a few years ago, having worked relentlessly to keep his son's killers behind bars.
His brother Steven took his own life in police cells in Australia. His son Thomas took his life not long after. Mr Crean's daughter spent more than two years in a mental health facility.
Liz Crean said she had no idea of her son's connection to the gang or the court case. After she found out he had been shot she went to the hospital, but did not make it in time. "I found a male nurse who had cared for Chris - he called me and shared his story of what happened," Mrs Crean recalled.
"Chris had given our names but couldn't remember the street or phone number ... it was shock. He did mention he was looking forward to becoming a father again."
Mr Crean's wife, Tania, moved away soon after her husband's death. An email was sent on her behalf to the Crean's family spokesman, saying she wished to leave the memory of her husband's murder behind and did not want to be part of any parole hearings or media coverage.
Mr Crean's family would like to see his killers stay in prison forever, but they accept their release is inevitable. They have tried many times to get the Parole Board to ban the men from the Taranaki area where they live.
This week, a Parole Board spokesman said: "The hearing is a hearing to consider parole. If the board decides an offender no longer presents an undue risk to the community they can be released.
"As part of any parole release the board considers conditions imposed on the offender very carefully and spends time on these.
"Community Corrections (Probation) manage and oversee conditions and issues like accommodation, work, and travel require permission. Travel where it requires approval in the condition needs to be specific, in terms of timing and location and is monitored by Corrections."
Mrs Crean said having a condition in place preventing her son's killers from coming near their homes and lives would bring closure.
"Why should they come home when Chris can't?"
