Before entering two mosques Friday in Christchurch, New Zealand, and opening fire on the unsuspecting worshipers, a man who made public his extreme white supremacist views had posted a 70-page anti-immigrant, Islamophobic "manifesto" on "white genocide," attempting to justify a massacre which is considered the worst in the country's history.

The alleged gunman has been identified by authorities as Brenton Harrison Tarrant, a 28-year-old native of Grafton, Australia. He had been living in Dunedin, New Zealand, at the time of the attack, was taken into custody by authorities after he targeting the Al Noor Mosque and the Linwood Mosque, both located in Christchurch.

On Friday, an important weekly day of worship within the Islamic faith, he proceeded to live-stream a 17-minute video of the 36-minute attack as he opened fire in both locations, killing 49 people and wounding dozens of others. 

To carry out his attack, Tarrant, who first acquired a gun license in 2017, used two semi-automatic weapons, two shotguns and a lever-action firearm. Two explosive devices were also found in his car.

All of the guns Tarrant used during the attack were purchased legally, according to gun laws and restrictions in New Zealand.

"There were two other firearms in the vehicle that the offender was in and it absolutely was his intention to continue with his attack," said New Zealand Prime Minister Jacinda Ardern in a statement to reporters on Saturday.

The video, which was live-streamed on Facebook, has since been removed from the platform.

Described by Australian Prime Minister Scott Morrison as "an extremist, right-wing, violent terrorist," Tarrant's manifesto made it clear that the gunman posited himself as something different: "just a regular white man."

In the manifesto, Tarrant identifies himself as "European" rather than as an Australian citizen and wrote that he grew up in the small working-class community in Grafton, located more than 300 miles northeast of Sydney. He described his background as Scottish, Irish and English and that he "had a regular childhood, without any great issues." 

Tarrant stated that hat he was "from a regular family" and that he "decided to take a stand to ensure a future for my people,” the alleged terrorist wrote of his background.

A self-described "ethno-nationalist," Tarrant worked as a personal trainer from 2009 to 2011 before beginning the first of many trips across the globe. It was during these later travels that he first became radicalized, according to the Associated Press. It is believed that his father's death from cancer in 2010 may have contributed to his radicalization.

During a tour through Europe, Tarrant witnessed an Uzbek man drive a truck into a group of tourists in Stockholm, killing five. The incident served as an origin story for Tarrant's later violent acts, according to the manifesto. 

Tarrant was also purportedly inspired to commit the mosque shootings by Norwegian far-right terrorist Anders Breivik, who killed 77 people in Oslo in 2011. Tarrant also appeared to be influenced by Dylann Roof, the young American nationalist who in 2015 killed nine black congregants in a Charleston church.

Despite mentioning Roof, it was Breivik, who he referred to as "Knight Justiciar Breivik," that he "took true inspiration from," wrote Tarrant.

The AP also reported that Tarrant, who has donated to a number of white nationalist groups but has no other direct affiliation with them, allegedly was given personal approval by Breivik to commit the mosque attacks in Christchurch, though this has yet to be verified.

Tarrant on Saturday was charged with only one count of murder, though Prime Minister Ardern assured the public that more charges will be added as the judicial process continues.

Prior to the shooting, Tarrant had no previous criminal record in either Australia or New Zealand and "was not known to authorities in connection with far-right violence,” according to Ardern.

While the main court proceedings will take place in New Zealand, there will be an investigation into Tarrant's background in Australia, according to Prime Minister Morrison.

“He is an Australian-born citizen,” Morrison said in an interview with The Telegraph. “That obviously leads to an Australian-based investigation and all of our inquiries here will be absolutely shared and communicated with New Zealand authorities.”

Tarrant is scheduled to appear in court again on April 5.