Colemen, 38, died in 2012 after being repeatedly tased by police. View Full Caption Facebook / Chicago Police Department

CITY HALL — With more than 30 years in law enforcement, Percy Coleman said he thought he'd seen everything. But nothing, he said, could prepare him for what happened to his son, Philip, at the hands of Chicago Police officers in December 2012.

Hours after the city surprised Percy Coleman by releasing a video of his son being tasered and dragged by police while in his holding cell (scroll down for video), he quickly organized a press conference to tell his side of the story.

"The police's actions that night ... if I told you people, you won't believe it," Percy said. "If you're waiting on the Chicago Police to tell the truth on a report, you can forget about that."

Percy Coleman, center, speaks about his son, Phillip's, death at the hands of Chicago police at this attorney's office downtown Tuesday. Jeffery Coleman (l.),Philip's brother, and Bishop Tavis Grant also spoke about Philip's death. View Full Caption DNAinfo/Joe Ward

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When Philip Coleman was taken into police custody near his parents' West Pullman home that December, concerned neighbors hoped he would go straight to the hospital.

He had recently gotten a divorce, was working a lot and went back to school, and something inside him snapped, his family said. Philip went home to talk to his mom, when his condition worsened and he attacked her.

Police were called, and after a struggle Philip was taken into custody, helped into the police van by his father, Percy said. But his son, a University of Chicago graduate and political activist in the community, did not make it to the hospital until it was too late.

He died after a bad reaction to the sedative he was given while at the hospital, according to authorities. But to truly understand his death, you have to know what happened to Philip while in police custody, Percy Coleman said Tuesday.

"Somebody in this city needs to be held accountable for the death of my son," he said. "The Chicago Police Department are at the head of the table."

Monday night, the mayor's office released a video showing six officers walking into the cell of 38-year-old Coleman and exchanging words with him before tasering him and dragging him out of the cell by his arms.

Watch the video here (the story continues below):

Officers at the Calumet District police station were attempting to take Coleman to court when police said he resisted and "became combative," leading officers to tase him and bring him to Roseland Hospital.

The family refutes the claim that Philip become combative. Philip was sleeping when the officers came in, and he sat up to see what the problem was, according to Ed Fox, the family's attorney.

He was tased and fell onto the cot when he was placed in a choke hold, Fox said. He lost consciousness and was tased three more before being dragged out of the cell, Fox said.

Philips was then taken to Roseland Hospital, where he was tased "up to" 13 more times, Fox said. Authorities had said he was being hostile to medical staff and others, and he was given a sedative.

Hours later, he was dead. The Cook County Medical Examiner's office ruled the death an accident, pointing to a bad reaction to the sedative he was given.

But that doesn't explain the more than 30 bruises and other physical injuries listed in his autopsy report (read it below), and authorities failed to expand upon why he reacted negatively to the sedative, Fox said.

“I do not see how the manner in which Mr. Coleman was physically treated could possibly be acceptable," Mayor Rahm Emanuel said in a statement accompanying the video's release, which happened without the approval or notification of the Coleman family. “Something is wrong here — either the actions of the officers who dragged Mr. Coleman, or the policies of the department.

The family has contacted leading doctors in the field, who have determined that the bad reaction to the drug was caused by the extreme stress and agitation Philips had undergone at the police station, Fox said.

"This is not an accidental death," Fox said. "They [police] set up a perfect storm to cause his death."

Percy and his family filed a lawsuit in 2012 alleging that police tried to "cover up" evidence that their own actions had led to his death. A court date has been scheduled for March 21, 2016, Fox said.

Percy didn't say that his family would deny a settlement from the city, but did say that he would relish his opportunity to testify as an eye witness to police's handling of the situation.

"I want you to see me on the stand, 'cause I've got something to say," he said.

The family said they gave police every possible indication that Philip had suffered a breakdown and that he needed medical attention.

"I had to stand in front of my son with my hands up" because police were going to shoot Philip, Percy said. "I said, how can you shoot him if he's out of his mind?"

An investigation into the incident by the Independent Police Review Authority has so far reached no conclusions, which Emanuel said was not acceptable.

"I have not received a sufficient answer on either from IPRA’s former leadership, and as a result I do not consider this case to be closed or the investigation into what happened that night to be over," Emanuel said.

Chicago Police interim Supt. John Escalante said the investigation was ongoing and vowed a "review of our policies and practices surrounding the response to mental health crises.”

In a Monday press conference announcing his appointment of Sharon Fairley as the new director of the Independent Police Review Authority, Emanuel said city leadership would "rededicate ourselves to dramatically improving our system of police accountability and rebuilding trust in that process."

Read Coleman's autopsy report:

M.E. Report (Coleman) (1)