The inquest into the death of Kingsley Burrell began last week.
In 2011 Kingsley called police to say he was being threatened by a gang while out with his young son, Kayden.
He was the taken by ambulance to a Birmingham mental health unit and sectioned under the Mental Health Act, but died four days later at the Queen Elizabeth Hospital.
His sister Kadisha Brown-Burrell was one of the first to give evidence. Kadisha said when the family visited her brother he was walking very stiffly and could not move his head, body and shoulders properly.
She told the inquest he had “a big lump on his forehead” and had deep cuff marks around his hands.
The Crown Prosecution Service found there was “insufficient evidence” to charge any of 12 people with Kingsley’s death.
They included four West Midlands police officers, two West Midlands ambulance staff, three nurses and three doctors.
Inspector Neil Allen was the officer who took the decision to section Kingsley.
He denied to the inquest last week calling Kingsley, “Mad, bad and dangerous”.
Allen, who is of African Caribbean heritage, said he would have acted in the same way if he had been dealing with a white man.
Kingsley’s partner Chantelle Graham also gave evidence. She said that an officer had alleged to her that Kingsley had banged their son’s head against the wall and that he had to be restrained.
But the court heard that her son told her a black police officer had started hitting Kingsley.
Chantelle said, “Kayden just kept saying, ‘The black police officer hit my daddy’ to anyone who would listen. That is what he told everyone, even at school.”
Kadisha also said that in the days after Mr Burrell’s death, Kayden had said, “The naughty black policeman did that to daddy.”
Allen told the inquest that Kingsley appeared “vacant and one dimensional” when he spoke to him in the back of an ambulance.
Karon Monaghan QC, representing Kingsley’s two former partners, asked Allen why the decision was taken to restrain Kingsley when he wasn’t being aggressive.
He said, “Force had been used and it was necessary to keep them on. A change of mind is all it takes to go from passive to aggressive.”
Kayden was slightly injured during a struggle in the ambulance when officers tried to restrain Kingsley.
The inquest is set to run for six weeks.