Thomas Mair may not have been overtly political as far as the outside world was concerned, but it became clear during the trial that his actions on June 16 were most likely fuelled by far-right beliefs.
In keeping with his quiet manner, these were views he largely explored through his choice in books and the life he led behind the safety of a computer keyboard.
Hours were spent in local libraries visiting sites such as the Occidental Observer, which covers “politics and society from a white nationalist and anti-Semitic perspective”.
His online research included right-wing politicians, the Ku Klux Klan and civil rights activists killed by its supporters, and the White Patriot Party.
We might never for certain know how much the EU referendum and campaigning in advance of the vote spurred him on to carry out such a public act of violence.
It seems though, based on the evidence, that one factor in his selection of Jo Cox as his target was that she had publicly declared herself a supporter of the Remain campaign.
A dossier of research carried out on Mrs Cox was found in Mair’s home in Lowood Lane, Birstall.
It included a column written by the Labour MP for the Batley and Birstall News and the Spenborough Guardian, in which she explained why she believed that the patriotic choice was to vote for Britain to remain inside the EU.
Mair had also visited the Wikipedia page of William Hague, another prominent Yorkshire political figure who had backed the Remain campaign.
There was even a leaflet about the referendum in the blood-stained carrier bag found by police in the holdall Mair dropped when he was arrested.
Eye witnesses described hearing Mair shout comments along the lines of “Britain first”, “Put Britain first” and “keep Britain independent” during his deadly attack.
And one of the two arresting officers reported Mair saying “I’m a political activist” after he had been handcuffed.
As well as trawling computers used by Mair at local libraries, police searched his semi-detached council home.
They found a gold Third Reich Eagle ornament with a swastika on it on his bookcase along with books on German military history and the Holocaust.
Police also recovered a double-page press cutting on Norwegian mass killer Anders Breivik and information on the BBB White Liberation Movement, a notorious South African neo-Nazi organisation.
Although Mair chose not to comment during his police interviews or to take the stand during his trial, he did make a highly political statement during his first appearance in court.
When asked to give his name, he answered: “Death to traitors, freedom for Britain.”
This continues to serve as the most public statement on his beliefs and what drove him to commit such a heinous act.