Chicago officials released video late Monday that showed a city police officer dragging a detainee through a hallway hours before the man died in a local hospital.

The video, taken in December 2012, shows six officers in a cell with Philip Coleman, a 38-year-old man who was taken into custody after allegedly attacking his mother as well as responding police officers. One of the officers appears to use a stun gun before another pulls Coleman out by his handcuffed wrists. 

A police report obtained by the Chicago Sun-Times claimed the officers were trying to remove him from the cell for a court appearance. The report said Coleman struggled and yelled at one of the officers, "Don't touch me, devil!"

The Sun-Times reported that Coleman was taken from the cell to a local hospital, where he allegedly struggled with police again and was shocked with a stun gun. Coleman died hours later. The medical examiner ruled that Coleman's death had been accidental after the hospital gave him a sedative.

A police review board previously found the officers' actions justified. But the interim police superintendent said Monday the matter is under investigation.

Chicago Mayor Rahm Emanuel said he didn't consider the case closed.

"I do not see how the manner in which Mr. Coleman was physically treated could possibly be acceptable," Emanuel said in a statement. "Something is wrong here — either the actions of the officers who dragged Mr. Coleman or the policies of the department."

The video is the latest in a series of encounters between the police and local residents that has drawn intense scrutiny. Last month, video showing a white officer fatally shooting a black teenager 16 times in October 2014 was released. The officer was charged with murder. 

On Monday, the Justice Department announced it would open an investigation into the Chicago Police Department.

Coleman's father, a parole official in the Illinois Department of Corrections, told the Sun-Times that he disagreed with the medical examiner's ruling and was considering suing the city.

"Chicago gangs and Chicago police think they can kill anybody in the community because they can — and it has to stop," Percy Coleman said. "They treated him like a dog ... Without the police’s help my son would be alive."

The Associated Press contributed to this report.

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