A Detroit-area police officer who hauled a man out of his car and repeatedly punched him in the head was charged Monday with assault stemming from a January traffic stop, which wasn't publicly known until a video was broadcast in March.

"The job of a peace officer can be dangerous," Wayne County Prosecutor Kym Worthy said. "But we cannot tolerate those who abuse their authority, violate their oath and prey on citizens rather than protecting them."

Recently fired Inkster Officer William Melendez was charged with mistreatment of a prisoner and assault, both felonies. Melendez has declined to discuss any specifics of how he treated Floyd Dent but said last week that "there are always two sides to every story."

The dashcam video shows Dent, 57, being pulled from his car by two officers during the stop on Jan. 28. He was repeatedly punched in the forehead by Melendez while on the ground, and is bloody when he stands up.

Worthy said her office didn't know about the incident until March 23, when WDIV-TV aired the video. Melendez, 46, a former Detroit officer, had not been disciplined until the story broke.

"We probably wouldn't know about it" without the video, Worthy said. Nonetheless, she declined to criticize the Inkster department.

A drug charge will be dropped against Dent, who claims a bag of cocaine was planted in his car during the arrest. A judge already has dismissed a charge of resisting police.

In 2004, Melendez and seven other Detroit officers were acquitted of lying, falsifying reports and planting evidence. Federal prosecutors had accused him and another officer of being the "masterminds" of a conspiracy to "run roughshod over the civil rights of the victims."

Separately, Worthy said there would be no charges in a Jan. 12 incident involving officers from Grosse Pointe Park and Highland Park who were investigating a car theft. An armed carjacking suspect, Andrew Jackson, was kicked and punched on the ground during an arrest in Detroit. A video was recorded by a woman in her home.

Some actions by the officers were "disturbing and inexplicable" but don't rise to criminal conduct, said Worthy, who added that it's up to the respective departments to order any discipline.

Jackson, who has filed a $1 million lawsuit against the officers, didn't cooperate with investigators who wanted to ask him about the arrest, the prosecutor said.