The Cincinnati Enquirer said William Westerkamp delivered an inflammatory 45-minute tirade of white supremacist statements on a police band Feb. 22.
Westerkamp, 32, was suspended without pay but was not charged with a hate crime. A Hamilton County grand jury Tuesday indicted Westerkamp for disrupting public services and unauthorized use of city property, both felonies.
"It is a clearly a matter where someone -- seething in staggering anger -- first lost their senses, then their job, and now it appears he may lose his freedom," county prosecutor Mike Allen said.
Westerkamp is scheduled for arraignment next week.