She heard how Bracken emerged smiling from the bush "dripping with blood", before stripping to his underwear to burn his clothes.
"It was devastating," Zelma said. "We learnt a lot of things about what happened to my son during the trial. It wasn't easy, we were shocked."
Zelma said she stared at her son's killer who showed no remorse as he whistled, sang and pulled hand signals at her family.
"He is one hell of an evil man who doesn't deserve to be in society with anyone else. He is all for himself, he doesn't care, he has no heart or soul."
At 7pm on Friday, after a "scary" six-hour wait, Zelma let out a sigh of relief, and tears flowed as she heard the word "guilty."
She said her son, and the community, finally got the justice they deserved.
Jack's 14-year-old son, Arahi Davis, held a photo of his father as they reminisced on their drove home to Auckland.
"They had just started to bond, going camping, pig hunting," Zelma said.
The boy wrote a message to his father on Facebook: "... saw your big huge smile today, pretty intense day in court, everyone shed a tear, but that b****** wayne got what he deserves," he wrote. "Its a real relief to know hes inside now, big huuuuge weight lifted off our shoulders, at least i can say that you can finally cross over with comfort ...my dreams are open for you, enter them anytime daddy."
Zelma said her son was a loving father who always put others first. "He helped a lot of people and had a lot of friends. He didn't deserve to get what happened to him."