A 31-year-old Northern California man has been sentenced to five years in federal prison for possessing a biological toxin and dealing in numerous firearms.

The U.S. Attorney's Office in Sacramento says undercover agents paid James Christopher Malcolm thousands of dollars for four assault-style rifles, ammunition, explosives, a silencer, three improvised detonation devices and equipment to convert handguns and semi-automatic pistols to fully automatic weapons.

The agents were posing as arms dealers for drug trafficking organizations. The 2-month undercover operation ended with Malcolm's arrest in 2014.

Malcolm, who lived in the Sacramento suburb of Carmichael, also was sentenced for possessing abrin, a natural poison that can kill within days.

Authorities say he shipped two vials of a rudimentary form of the poison concealed within flashlights in late 2013.