A private investigator who was caught on camera in an anti-Muslim rant against London Mayor Sadiq Khan has been jailed for 26 months.
Police found a stash of material on Pawel Golaszewski's computer, including weapon-making instructions and "silent assassination" techniques.
A judge at the Old Bailey said the 34-year-old's views were "Islamophobic and of an extreme right-wing nature".
Golaszewski, from Leeds, had previously been convicted of terror offences.
The court was told Golaszewski, of Wensleydale Mews, Armley, was arrested in February by Counter Terrorism Police.
He claimed he had obtained the documents as research for work as a security guard and private investigator, and said he had an ambition to join the army.
At his home police found a sheathed knife on the wall, two smoke grenades, a lock-knife and a torch with a concealed knife.
In a video retrieved from his hard drive, the defendant described Mr Khan in racist terms and voiced "anti-Muslim and anti-immigration" views.
Golaszewski had denied six counts of possessing terrorist documents but was found guilty on all charges.
Judge Rebecca Oulet QC said: "Most of these texts contained viable recipes and clear instructions for workable explosive devices or IEDs.
"These were written for someone without expert knowledge.
"They provide step-by-step instructions to inflict serious harm or death on a victim, including silent assassination techniques."