It has been more than two years since the "senseless" daylight shooting murder of NSW Police accountant Curtis Cheng and his son, Alpha, continues to speak out against violence.
He says it helps him cope with the loss of his father.
Mr Cheng, whose father was shot in the back of the head as he left work at the Parramatta police headquarters in October 2015, urged people at a Holocaust education exhibition at Victoria's Parliament House not to give in to prejudice.
"It is part of a process ... (in) trying to find meaning and purpose to a senseless act," Mr Cheng told AAP after speaking at the Courage to Care exhibition on Tuesday.
The program encourages high school students to stand up against intolerance, prejudice and discrimination.
"The assailant that shot my father, we must not forget that he was a 15-year old and there has to be something quite tragic that has happened in society where young people don't feel like they belong ... that will allow such terrible things to happen," Mr Cheng said.
Schoolboy Farhad Jabar was shot dead by police shortly after killing Curtis Cheng.
His son has since used his grief to publicly advocate against racism and intolerance.
He is angry politicians used his family's tragedy to "whip up sentiments of hate or suspicion across various groups in our community".
Mr Cheng was referring to One Nation Senator Pauline Hanson's comments in July 2016, when she said "we know for a fact that the young 15-year-old who killed Curtis Cheng got the gun from a mosque".
Mr Cheng is scheduled to address Parliament House again on Friday, to coincide with the close of the Courage to Care exhibition.
