Deputies Ryan McGowan, 31, and Thomas Lu, 42, both of Elk Grove face charges of trafficking in handguns that cannot be legally bought by citizens in California, including some exotic weapons such as high-powered rifles mounted on pistol frames.
U.S. Attorney Benjamin Wagoner said the deputies served as straw buyers by purchasing the restricted handguns, and then selling them at a profit to unqualified buyers. Authorities say at least two of those weapons fell into the hands of criminals.
"When law enforcement officers misuse their badges to funnel dangerous weapons to the highest bidder, they compromise the safety of the public," Wagner said at a news conference. "By putting personal profit ahead of public safety, they undermine the very essence of their duty."
California law bars citizens from buying handguns that have not been deemed safe by the state Department of Justice, but the law exempts peace officers. The deputies are accused of using their peace officer exemption to buy dozens of weapons over more than a year.
The weapons include semiautomatic pistols that shoot high-velocity .223 caliber bullets, the same long-range ammunition used by the U.S. military for its M16 and M4 rifles. Also sold were handguns that fire .50 caliber pistol bullets, a less powerful version of the same large-caliber round used in machine guns and sniper rifles. Investigators say semiautomatic handguns built to look like Israeli-made Uzi submachine guns were also bought and sold.
Also charged were firearms dealer Robert Snellings, 61, of Rancho Murieta and Ulysses Simpson Grant Early IV, 36, who is accused of buying guns. Both are from Sacramento.
Two other police officers, one in Sacramento and the other in nearby Roseville, were implicated in the investigation but have not been charged. Both have since lost their jobs.
The Associated Press contributed to this report.