The attack occurred in March in a leisure centre car park, where Bowles used two knives to stab the woman multiple times. He admitted to the crime, explaining he was driven by issues with the "murky waters of ethics" and his views on the US National Security Agency (NSA).
The attack was described as "politically motivated" by the senior judge, who noted Bowles' resentment towards GCHQ and women. Online searches by Bowles included references to US Unabomber terrorist Theodore Kaczynski and white supremacy.
The victim, who worked in the same place as Bowles, said the assault had deeply affected her life. Another man, Alex Fuentes, was punched by Bowles during the incident. Authorities credited the intervention of witnesses at the scene with likely saving the woman's life.