Complete BS on your part. The "explosive device" that they made were pyrotechnics and they threw some molotovs against a wall. The "disseminating leaflets calling for the attacks on law enforcement" were political leaflets that included slogans such as “the FSB is the main terrorist" that they hung on the local FSB office.
Police state-they sentenced Uvarov to five years in a penal colony.
Find a report detailing the trial in the source which is not a liberal propaganda.
As a side note, what do you think Molotov cocktail is, according to the National firearms act?
Educate yourself on what a destructive device is.
https://en.wikipedia.org/wiki/Destructive_device
It is illegal by federal law to manufacture and possess one.