Speaking for the first time since her son's killer was jailed, Lichelle Mills slammed Cooper's sentence as "a joke" and "wasn't long enough".
"I'm just livid. It was bad enough coping with the loss of Javed and in the end all you hope for is justice. When you feel like you don't get that it's just horrifying," she said.
"Not only did he take his life, he violated his remains. I couldn't even bury him complete in that sense."
She said she could not prevent the appeal and would have to let the law take its course but she would attend any of Cooper's parole hearings. "We would like to keep him [in prison] for the duration," she said.
Cooper was tried for the murder in August last year. The jury found him not guilty of murder but guilty of manslaughter. The court heard Cooper "lost his marbles" and killed his friend in July 2009 after a row.
Cooper had elbowed Mills in the head in an oversized doll house called "the den", where Mills was secretly staying. After he killed him, Cooper had wrapped his friend in a blanket and hidden the body underneath the den for a couple of days.
He had later buried Mills in a shallow grave and maintained an elaborate ruse that he was still alive for 12 months. He withdrew Mills' Winz benefit and also set up a fake Bebo account to give the impression he was alive and living in Wellington.
He then exhumed the remains and crushed the skull into small pieces with a hammer to hamper any police examination.
The rest of the remains were put in a wheelie bin and about six to eight months later it was placed at a derelict house due to be demolished.
Demolition workers found the remains in September 2011.
