"David Hoeft and two of his friends, they're called the GBak Crew from Auckland who are professional graffiti artists. I asked them as a favour to come and work on the mural so we could put the message out there.
"As soon as we started putting the mural up, the number of young people that stayed to watch was amazing. There was an automatic reaction from the community."
The mural features a picture of Kirisome's face and Mr Oli-Alainuuese said he had not told his parents about the project until after it was completed.
"My dad was speechless and emotional. My family loved it and it's just changed the whole atmosphere of Flaxmere.
"This is something positive for everyone here. When it's [graffiti] done professionally, it does have a good impact."
Kirisome, who also went by the nickname Someh, was 18 when he died. He was a role model for younger people, a good dancer and a champion sportsperson who featured in the Hastings Boys' High School First XV team this year.
"And he had some school friends who dedicated their Pacific festival performance last weekend to my brother. So I want people to remember him how he lived, not the way he died. I don't want these young ones who looked up to him to follow the last moment of his life."
Mr Oli-Alainuuese said his brother found it challenging accepting the strict Samoan culture his family embraced and struggled with social problems.
"What I think we need to do is really get involved in school programmes for youth, do stuff for kids and get them off the streets so we get to know our children better to find out what their problems are.
"I am a barber, that's what I do for a living and my ambition now is to open up a barber shop here in Flaxmere to give free lessons for young people to learn to cut hair.
"I want to give them a chance to learn a new skill to give them something to focus on."