Sheakalee, 59, was formerly a federally sanctioned arms dealer, but he lost his license this year, ABC reports.
In June, the state institutionalized Sheakalee three times for mental health issues, believing that he was a danger to himself and others.
By California state
After being institutionalized, Sheakalee missed a court-mandated deadline for relinquishing his guns, and was subsequently was charged with illegal possession of firearms.
During a raid on Sheakalee's home, agents seized 209 handguns, 88 shotguns, 234 rifles, 181 standard capacity magazines, 10 high-capacity magazines, 100,521 rounds of various ammunition, and 10 assault weapons including a .50 caliber bolt action rifle, which are banned under California law.
"Removing firearms from dangerous and violent individuals who pose a threat to themselves and the public is a top priority for the California Department of Justice," California state attorney general Kamala D. Harris in the statement.