34 year old Lucy Miah, who was based at Mount Browne, had pleaded not guilty to assaulting a woman who was known to her, but the magistrate determined the evidence proved she had.
She was ordered to pay £650 in costs and £48 in surcharge.
Miah was restricted from public facing duties following the incident and has since been suspended following conviction, pending the outcome of misconduct proceedings.
Head of Professional Standards, T/Chief Superintendent Andy Rundle, said:
“We are pleased that the victim in this case felt confident enough to report this incident to us and hope this goes some way to reassure other potential victims that we will always thoroughly investigate reports of assault.
“I encourage anyone who has been the victim of violence, including police-perpetrated, to come forward and report this to us. We will take you seriously.”