Jack Robinson, 20, from Portsmouth, pleaded guilty to various offences at Winchester Crown Court on 10 May 2024.

Robinson, who held Nazi views, began sharing antisemitic views at the age of 17, frequently referencing Hitler and Mein Kampf on social media site Discord.

When police searched Robinson’s home following his arrest, working parts for a semi-automatic gun were found, alongside instructions for how to 3D-print and assemble the weapon and 1,253 ammunition and nail gun cartridges.

A weapons expert tested the printed parts and found that they all worked and that the gun was capable of being used as a lethal weapon.

Robinson also had documents containing viable instructions on how to make firearms, ammunition, explosives and improvised explosive devices (IEDs).

He had also written a note demonstrating his beliefs in various antisemitic conspiracy theories and had ‘execution’ videos showing young men being killed under a swastika flag.

The Holocaust denier owned various pieces of Nazi memorabilia, knives, stab vests and had conducted over 3,000 searches for extreme right-wing content online.

At a separate hearing, Robinson also pleaded guilty to two charges of making indecent images of children and two charges of possessing indecent images of children. Over 700 images and videos were discovered during the search of Robinson’s electronic devices, most of them Category C, with at least one being a Category A image.

Most of the material featured children aged between six and 10 and one of a child aged between three and five years old, or cartoon or CGI generated images.

Frank Ferguson, chief crown prosecutor of CPS Special Crime and Counter Terrorism Division, said: “Jack Robinson held extreme views and intended to act on them using the lethal weapon he was creating.

“Robison had over 1,000 gun cartridges and had instructions on how to make explosives which is a clear indication of the devastation he could have caused. He had called for death online and held extreme Nazi and racist views.  

“Today’s sentencing shows the seriousness of his crimes and helps protect the public by removing him from the streets.”