Shaun got into boxing and by the time he was 12, he'd fought about 500 fights.
"There are photos of my Dad holding my hand up with my two front teeth knocked out when I was about seven or eight."
Shaun and his immediate family moved to New Zealand when he was 12, where his father found a job. Shaun kept up his boxing training and travelled the world. In his mid 20s, Shaun got a call to say his father was dying of cancer so he flew back to New Zealand to see him.
It was then that buried family issues came to light that allegedly implicated a man outside of the family. From his death bed, Shaun's father asked his son to "sort it out".
"To me that was kill [the guy]. That was how I thought."
Fast forward five years and Shaun says upon being released from prison, he struggled to adjust to life on the outside without rehabilitative support.
"When you get out they don't give you any protection, they kept moving me around [between half-way houses] because I kept getting into fights. There were people trying to kill me, stabbed three times and shot once. I don't think prison is very much rehabilitative, it is more punitive, there is no sort of rehabilitation.
"In prison you walk on one side of the hallway, and you follow the guard. If you bang into anyone it is for a reason. So I became really hyper aware, I couldn't be in crowded places. If someone bumped into me I was ready to just give it to get them, for protection."
When Shaun got into a relationship, he constantly fought to suppress his inner demons.
"Getting into a relationship is really hard. In the gang scene there is no respect, it is fear of consequence. People say 'oh they respect him' but they don't, it is the fear of the consequence that stops them doing it. So when you get into a relationship it is really hard to go from a place where you're feared and have all this power and control over people.
"You come out and you have all these insecurities about who you are as a person because you've done some really bad things to people, then to try and go into a normal living situation in normal society it is so difficult."
Shaun said he would yell and scream when he reached boiling point.
"You don't get any sort of counselling when you come out of prison. We would disagree on something and I always had to have the last say. But it can't be like that in a relationship. You have to give and take. I couldn't understand that. From what I have always seen if you are violent enough you get what you want."
Shaun says he'd go from zero to "explosive".
"To me, [my partner] knew not to push me, so I'd have a right to blow up. But I don't! I had this thought that I can do what I like because she's pushed to that point and she knows what the consequences are going to be."
But becoming a father was Shaun's wake-up call.
"I didn't want her to see that. I was embarrassed. I want her to meet a man that treats her with respect and is good to her and lets her be who she is. For me to now be that to their mum is critical."
Shaun believes its imperative children should be educated to prevent the cycle of violence from continuing.
"Boys see their dads hitting their mums, they think that is normal so when they get to their relationship they think that is normal.
"They don't know any different. If I had the opportunity at 12 to know this was not okay, I would not be here."
Shaun and his partner are no longer together but are working together for the children and do not want their home to be "broken".