Note three things: de facto the gunman is being put on trial not for mass murder but for his alleged ideas.
Conspiracy theorists are busy discrediting themselves by denying that the attack was real or that anyone was killed
https://jamesfetzer.org/2019/03/scott-bennett-the-new-zealand-shooting-what-happened-and-why/
They are quite aggressive towards anyone who tells them they are deluded
Harold Saive says “Max Igan is wrong (or lying) in his analysis of the Tarrant video.
A reasonable person would never agree with Igan that the video proves people were really shot.
Analysis by Scott Bennett, former military. Open your eyes and assimilate” (from Harold Saive)
Here is a plausible analysis from Max Igan
https://www.youtube.com/watch?v=BVFo3UUnIGQ
Also, factor in this input from Suzie Dawson:
https://consortiumnews.com/2019/03/15/misguided-spying-and-the-new-zealand-massacre/