DETROIT, MI -- Wayne County Prosecutor Kym Worthy on Monday charged ex-Inkster Police Officer William Melendez with two felonies for his involvement in the violent Jan. 28 arrest of 57-year-old Floyd Dent.

Worthy also dismissed an open felony cocaine possession charge against Dent, stating, It was "in the best interest of justice." She declined to elaborate on whether she believes Melendez planted the drugs, as Dent and his attorney, Gregory Rohl, insist.

The Inkster Police Department fired Melendez last week.

A separate police brutality investigation of Highland Park Police Sgt. Ronald Dupuis and Grosse Pointe Park Sgt. James Volger yielded no charges.

"We cannot turn our heads when a law enforcer becomes the law breaker," Worthy said. "At the same time, this office will not press a charge against and officer -- or anyone else for that matter -- if it can't be proven in the court of law under the appropriate evidence and no matter what is being said in the court of public opinion."

Worthy said both investigations have concluded and did not provide arrest or arraignment information on Melendez. He's charged with misconduct in office/mistreatment of a prisoner, punishable by up to five years in prison; and assault with intent to do great bodily harm, punishable by up to 10 years in prison.

Both investigations were prompted by videotaped arrests and involve officers with checkered pasts.

Jackson, 51, was beaten by Dupuis, who's worked for three other departments and faced prior allegations that he shot his partner with a Taser, arrested a man without cause and choked a woman in jail.

Melendez, who worked for the Inkster Police Department until being fired Thursday, earned a reputation as an aggressive cop and the nickname "Robocop" while previously working for the Detroit Police Department.

Melendez has been named in a numerous civil lawsuits filed by plaintiffs claiming he violated their civil rights.

Jackson, a parolee with at least 16 aliases and a tattoo of a machine gun on his left bicep, has a criminal history that traces back more than two decades. He has since been charged with 11 felonies, including armed robbery and carjacking, in connection with his Jan. 12 arrest.

Police say Jackson carjacked a woman and her two grandchildren at gunpoint. He was arrested by a multi-agency auto theft task force based in Grosse Pointe Park and is set to go on trial June 15.

A resident caught Jackson's arrest on video with her cell phone. It's since garnered over 1.3 million views.

Posted by Emma Craig on Monday, January 12, 2015

The video shows Dupuis straddling the back of Jackson, who is face-down. Dupuis punches the man several times in the head while his partner adds a couple kicks before Jackson is handcuffed.

Jackson can be heard muttering something.

"What'd you say?," the officer who kicked him says while kneeling in the center of Jackson's back. "Jesus? You're calling Jesus?

"You (expletive)! Don't you dare; don't you (expletive) dare."

Worthy says Jackson "refused to cooperate through his lawyer with this investigation."

"It is clear he was a felon attempting to flee, and when apprehended was armed with a weapon while he ... resisted the attempts to arrest and refused to surrender his right hand for cuffing," Worthy said. "Sgt. Dupuis does appear to have minor contact with Mr. Jackson once this arrest is complete.

And although the contact is improper ... it does not support a criminal charge."

Worthy suggests the department punish Dupuis internally.

She says Volger struck Jackson in the thigh "with a recognized and accepted technique."

In the case of Dent, he and and his attorneys claim, after being punched in the head 16 times by Melendez, and kicked and shot with a Taser three times by another officer, police planted cocaine.

Dent was originally charged with possessing crack cocaine, driving on a suspended license and resisting and assaulting a police officer.

Melendez remains employed as a part-time police officer with the Highland Park Police Department.

State police investigated both arrests and forwarded their findings to the Wayne County Prosecutor's Office.