A Fife police officer injured while confronting Sheku Bayoh in Kirkcaldy feared she was going to die, according to her father.
Nicole Short, 32, was one of the officers who responded to calls from the public reporting a man carrying a knife in the town on May 3, 2015.
Her dad Thomas, 57, said the family had not been able to give their side of the story while the matter was under investigation.
The Lord Advocate last week revealed no police officers would be prosecuted over the death of Mr Bayoh, who became unresponsive after he was restrained.
“We have been forced to stay silent for three years, knowing the truth of what happened that morning yet yet not being able to talk about it because of proceedings,” Mr Short told The Mail on Sunday.
He added: “She was scared. She thought she was going to die. She turned and started to run but he caught up quickly and she felt his fist suddenly connect with the back of her head.
“The force of the punch lifted her off the ground and she flew through the air head first, landing on the tarmac.
“She remembers coming round and being dragged to safety.
“But while she was unconscious, onlookers say he was stamping on her back.”
It is unlikely that Miss Short will ever return to front-line policing again after the incident, which left her with facial nerve damage, and also knee and back injuries.
And Mr Short said his daughter had been psychologically scarred by what happened.
“She still has nightmares and is a shadow of her former self.
“She’s gone from being an outgoing girl to living in various states of fear.
“It’s heartbreaking to watch. All we can do is support her.”
Following the Lord Advocate’s decision not to prosecute officers, Mr Bayoh’s family said they had been failed by the justice system.
The family’s lawyer Aamer Anwar said they would accept nothing less than a public inquiry by the Scottish Government into the death of the 31-year-old father of two.
But Mr Short said the officers involved in the case had been “vilified”.
He added: “The officers in this case are not allowed to speak out publicly, yet they’ve been unfairly vilified and I think the public will be shocked when they know what actually took place.”
Mr Anwar said Mr Bayoh had acted out of character and it was now known that he was not carrying a knife when police arrived.
“Sheku Bayoh was under the influence of drugs but he did not deserve to die,” said the lawyer.
