Malcolm Rewa conviction: How the justice system got it so wrong

A law professor is taking no comfort in the judicial system after it took three trials to find Malcolm Rewa guilty of murdering Auckland woman Susan Burdett.

Prof Chris Gallavin of Massey University says the prosecution erroneously condemned then 17-year-old Teina Pora for Rewa's crime.

"I don't regard somebody being convicted of a crime that they manifestly, obviously had nothing to do with, and serving a 22-year prison sentence, as indicative of the system getting it right and the system working."

Rewa is already serving sentences for 25 rapes. He was convicted of Ms Burdett's rape in 1998.

Ms Burdett's body was found in her Papatoetoe home in March 1992. She suffered five or more blows to the head with a blunt object.

Prof Gallavin says during the first two trials, the prosecution's version of events included the innocent Mr Pora.

"This one - the third trial - was pursued on a fundamentally different theory, and that was that Malcolm Rewa was a person that was acting alone."

Prof Chris Gallivan.
Prof Chris Gallivan. Photo credit: The AM Show

Rewa's defence was that he and Ms Burdett had a romantic relationship, and she was killed by someone else.

His sentencing is set for March 26.

"It's highly likely that we would have been in this situation in the first trial had the Crown not erroneously pursued the theory that Teina Pora was involved," said Prof Gallivan.

Mr Pora's convictions were quashed in 2015 after reporters delved into the story and found significant problems with the official version of events.