Australian Brenton Tarrant killed 51 people and injured 40 after he opened fire at worshippers at two mosques in the city of Christchurch in New Zealand on March 15, 2019.
The white supremacist, then 28 years old, stormed the Al Noor mosque armed with semi-automatic guns and shot at Muslims gathered there for Friday prayers, killing 44.
This was filmed from a head-mounted camera and streamed on Facebook as he headed to Linwood Islamic Centre about 5km away and killed another seven people.
Tarrant, born in New South Wales to a father who was a garbage collector and a mother who was a teacher, had moved to New Zealand in 2017 and started planning attacks against the Muslim community.
In his 74-page manifesto titled The Great Replacement which he published before the attack, he wrote that he wanted to ensure a future for white people, and described the immigration of non-European people to Western countries as "white genocide", among other things.
Tarrant described himself as "a regular white man, from a regular family" and said he did not hate foreigners or Muslims who lived in their "homelands".
But he said immigrants were invaders who colonised other people's lands.
He was sentenced to life in jail without parole last August - the first terrorism conviction in New Zealand's history.
The New Zealand judge who sentenced him had said the sentence was not enough punishment for the "wicked" crimes.
He said Tarrant had shown no remorse and that no matter how long he spent in prison, it would not be long enough to atone for his crimes.