Prosecutors said Friday that 42-year-old Hialeah police officer Rafael Oscar Valdes and 45-year-old Tammy Lynn Valdes were charged with dealing firearms without a federal license.
That carries a maximum five-year prison sentence.
Rafael Valdes also is charged with making a false statement regarding a firearm.
That carries a maximum 10-year sentence.
Authorities say the couple sold at least 100 firearms over the Internet to people in 44 states since 2005.
They also allegedly sold more than 500 weapons at gun shows.
The indictment says nine weapons were sold to undercover agents.
Court records did not list attorneys for the couple.
Their arraignment is set Jan. 11.