And after a failed parole stint in 2011, when he was recalled for hanging out with a criminal and drug addict, Purdy was granted parole again in February last year.
But his newfound freedom lasted just over a week.
Almost immediately, Purdy started breaching his parole rules by leaving his given address at night and using a cellphone.
On March 7 last year, police caught him approaching prostitutes in a central city - the exact location has been removed in a new decision by the parole board.
As well as the prostitutes breach, he also escaped custody on March 28 last year during a Christchurch Hospital appointment - only to be caught 250m away.
He had just finished a medical appointment when two Corrections officers took his handcuffs off to put him into the single cage compartment of the van.
It was then that he saw his chance to dash for freedom.
Purdy ran off with one Corrections officer chasing on foot, while the other pursued in the van.
He was captured in Cashel St, near Rolleston Ave, some 250m metres away.
The only explanation he could offer was: "It just happened."
In its decision to decline Purdy another shot at parole, released to NZME. News Service, the board commented: "It is fair to say that Mr Purdy has not previously responded well when granted the privilege of parole."
A Christchurch District Court judge sentenced him to three months' imprisonment, to run concurrently with his life term.
The parole board noted that Purdy needed "significant work" before he could be considered for parole again.
A psychological assessment found that while he reacted well to treatment, he "quickly falls back into rule breaking behaviour" upon release.
"Until Mr Purdy has been able to demonstrate such change for a sustained period in prison we are of the view that given his past failures on parole he remains an undue risk to the safety of the community," the parole board said.
