THE mother of slain teen Harrison Geppert had a "feeling" it was her son killed in a stabbing and tried ringing him relentlessly before realising she was right.

Lisa Geppert - mother of notorious former Hells Angels Bikie Ben Geppert - has spoken publicly for the first time about the death of her fifth child, Harrison, who died from a stab wound in Frascott Park, Varsity Lakes on September 4, 2019.

Ms Geppert opened up in a recent gang and prevention video series - alongside her ex-bikie son - about the impact of the criminal lifestyle on her family.

Former bikie Ben Geppert.
Former bikie Ben Geppert.

She said on the night Harrison died she thought she was going to have a heart attack.

"But, I was happy to have a heart attack. I had no care about myself whatsoever, I didn't, at that point in time I didn't think about anything except that how was I going to live without my child. How do you go on from that?" she said, in the Exit Program video, produced by the Queensland Police Service and National Anti Gang Squad.

Ms Geppert said on the day of Harrison's death she read a news article about a stabbing and feared the worst.

"I just had this sick feeling come over me and just had this feeling that it was Harry," she said.

"I tried calling him. And calling him and he wasn't picking up.

Lisa Geppert has opened up about the death of her son in a gang exit video.
Lisa Geppert has opened up about the death of her son in a gang exit video.

"My husband was out on the phone out the back talking, he came in, I said that I'd seen this story on 7NEWS and I can't get hold of Harry. He looked at me like I was crazy for even thinking it, saying it."

She said she felt like she was "looking down on somebody else's life" as if it was a movie.

But it was reality, she said.

"A minute later Ben (Geppert) rings and said he heard it was Harry. That's when life was turned upside down."

Ms Geppert said on the day of her son's funeral she had never shaken so much.

Harrison Geppert died from a stab wound at Varsity Lakes.
Harrison Geppert died from a stab wound at Varsity Lakes.

"I felt sick. It was the longest day of my life other than the Wednesday Harry was taken away," she said.

"Planning your own child's funeral is one of the most gut-wrenching, heart-breaking thing you can ever do in your life.

"You should never have to bury a child. This is going to affect us for the rest of our lives. As a mother, I gave birth to him. He's always in my mind and for us it's a life sentence. None of us will ever get over it."

Speaking in the video, Ben Geppert - who on Tuesday was committed to stand trial for a string of serious charges - said he partly blamed himself for his brother's death.

Jarvis Jai Farrier, 19 has been charged with murder over Harrison's death and has been committed to stand trial in the Supreme Court.

Originally published as 'For us it's a life sentence': Mother's grief over son