A former Memphis police officer pleaded not guilty on Wednesday to civil rights charges in the jailhouse beating of a transgender prostitution suspect that was captured on video.

An indictment unsealed Wednesday accuses Bridges McRae, 28, of using unreasonable force by repeatedly striking Duanna Johnson with his fist and handcuffs in the intake area of the Shelby County Jail in February.

Johnson, a biological male who lived as a woman, was being booked on a prostitution charge when the incident happened. A videotape of the beating was broadcast on Memphis TV stations and online in June, leading to McRae's firing. His former partner, James Swain, 25, was also fired.

McRae pleaded not guilty at a brief hearing on Wednesday before a federal magistrate and was released without bond. No trial date was set.

He is charged with violating Johnson's civil rights while in a position of authority, an offense that carries a maximum punishment of 10 years in prison and a $250,000 fine.

Johnson, 43, who had a long history of prostitution arrests, was shot to death on a Memphis street by an unknown assailant earlier this month. The killing is still under investigation and no arrests have been made.

McRae declined comment as he left the federal courthouse. His lawyer, Ted Hansom, said McRae was "in a scuffle" with Johnson, who stood 6-foot-5 (1.8-meter), and was doing what he had to do to defend himself. Johnson was knocked bleeding to the jailhouse floor but was not seriously hurt.

The beating and Johnson's murder have drawn the attention of advocates for gay and transgender rights, including the Human Rights Campaign, a national group that has called on the Memphis Police Department for a "commitment to treating transgender people with respect and fairness."