The IOPC said officers had received a report that four black boys aged around 14, three wearing black puffer coats and one wearing a dark blue hoody, had robbed a phone from a 13-year-old boy.
One of the robbers was said to have claimed they had a knife, although the victim did not report seeing a knife, the IOPC added.
Child B, who was visibly upset, told officers he had come from school and was wearing his school uniform under the hoody, the IOPC added.
The incident was seen by members of the public and mobile phone footage recorded by a witness was analysed by investigators from the IOPC, along with officers’ body-worn video.
The watchdog said on Thursday that an independent panel found the officers’ actions amounted to misconduct.
Specifically relating to the use of force for handcuffing the child for longer than necessary, and for equality and diversity for failing to make reasonable adjustments for the boy.
