Matthew Downs, an inspector with West Midlands police, also turned a cell light off when the 17-year-old detainee said he was scared of the dark, a disciplinary hearing on Tuesday heard, The Guardian reported.
Downs said the detainee had been aggressive and he had reacted “instinctively” but admitted he had made a mistake and let himself down.
The youth, referred to as AB, was taken to Oldbury’s custody suite after being “red-dotted” with a Taser when he threatened someone with a machete while drunk in Walsall in February last year.
Presenting Counsel Andrew Waters said custody block inspector Downs, 49, watched other officers carry out standard search procedure on AB before becoming involved.
Waters told the misconduct panel, “He entered the cell and used unnecessary and gratuitous force on AB – in particular in picking him up … pushing him around.”
“In addition he was abusive to AB in two instances. He shouted and swore at AB and, when AB started crying, he mocked him for doing so,” Waters said.
“As he left the cell, he asked AB if he was afraid of the dark and, when AB said he was, he said ‘Good’ and turned the light off,” he added.
Giving evidence after CCTV footage of the incident in the cell was shown to the panel, Downs, who has served in the police for over 22 years, said the detainee had behaved aggressively.
“I just wanted to tell him to behave himself,” Downs said, adding, “As the officers were leaving the cell, AB made a threat. It was along the lines of ‘You see what happens now’, which I reacted to instinctively.”
After viewing the CCTV footages, Downs said, “It was a mistake, I shouldn’t have done it. I have let myself down.”
Adrian Keeling QC, representing Downs, urged the panel to impose a final written warning. The youth involved did not make a complaint about Downs, the hearing was told.
Keeling argued, “The culpability and harm is low. It’s a single incident and it’s in no way targeted or planned – it arises out of a spontaneous set of circumstances.”
Downs said he would “absolutely” agree to be reduced in rank if the panel decided to impose it as a sanction, adding, “I am proud to serve.”
The outcome of the hearing is due later on Tuesday.