Federal authorities arrested a man in Carmichael late last night, for allegedly making machine guns and explosives.
A two-month investigation was cut short when federal authorities believed James Christopher Malcolm figured out his was being investigated.
The Sacramento Bee reports that's when federal agents moved in late Sunday night and arrested him for manufacturing and selling automatic weapons and explosives.
Agents were working off information from an informant.
During the investigation, agents bought illegally altered AR-15 rifles and glock handguns from Malcolm.
He remains in custody until his hearing on Wednesday.