A police officer has been found guilty of assaulting a man with a Taser.
British Transport Police constable Andrew Spiby was sent to a reported disturbance at Derby railway station on 28 May.
The suspect also had "incapacitant spray" used on him and later complained about the level of force used, Birmingham Magistrates' Court heard.
Spiby, 55, of Suffolk Avenue, Derby, denied a charge of common assault and will be sentenced on 10 June.
A second officer facing the same charge was cleared.
A two-day trial ended on 12 April but the verdicts have just been announced.
The Independent Office for Police Conduct (IOPC) began an investigation in July and the Crown Prosecution Service authorised the charges in January.
IOPC regional director Derrick Campbell said: "This was a serious incident which was witnessed by onlookers, including several young people.
"Police are entitled to use force but only if it is necessary, reasonable and proportionate in the circumstances."
Deputy chief constable of British Transport Police Adrian Hanstock, said: "Both officers were responding to a challenging situation where members of rail staff feared for their safety, and called officers to assist.
"That said, clearly on this occasion the court felt that excessive force was used and found PC Spiby guilty of common assault."
He added that the court's findings would be reviewed and "any potential misconduct action will be proportionate to the full circumstances the officers encountered".