A former detective has been criticised by a judge after being found guilty of damaging a car during a road-rage incident.

Andrew Kennedy was told his actions in throwing his bike onto the bonnet of a car were "entirely futile" and achieved nothing.

District judge (magistrates) David Thomas was told how Kennedy reacted when a stand-off occurred in Ilkley town centre.

Kennedy, who was a serving officer at the time although off-duty, confronted motorist Robert Stell and accused him of causing two near-accidents.

Mr Stell claimed Kennedy twice picked up his cycle and slammed it on to his car bonnet, causing damage estimated at £1,500.

Kennedy - who retired from the West Yorkshire force last December after being injured on duty - insisted he had placed his machine on the bonnet to prevent the vehicle being driven off.

He claimed at Bradford Magistrates Court: "It's my practice not to get involved in incidents with motorists unless I really need to."

But other motorists described how they saw him shouting angrily at Mr Stell and trying to snatch the keys from the car's ignition during the incident at the junction of New Brook Street and Church Street.

Kennedy, 43, pleaded not guilty to disorderly conduct and causing criminal damage. He was cleared of the first charge, but convicted of criminal damage. He was ordered to pay £500 court costs and £100 compensation to Mr Stell.

Announcing his verdicts at the end of the three-day trial, district judge (magistrates) Mr Thomas said he could sympathise with how Kennedy felt after the officer's son was almost knocked off his cycle by the "erratic driving" of Mr Stell.

He told Kennedy: "I have considerable sympathy for your position, but you went beyond your powers."

Mr Thomas said what he found "entirely futile" was that Kennedy had either put or slung his cycle on to the car bonnet.

"What on Earth could have been achieved by that?" he asked.

The court heard that the incident happened last April when Kennedy was off-duty and part of a group of cyclists returning from a run to Bolton Abbey. Fellow cyclist Ralph Eastwood said he saw Kenn-edy lift his bike on to the bonnet to prevent the vehicle moving away.

"He did not slam it on to the bonnet," he added. "He beh-aved exactly how I would expect a good police officer to behave in that situation. He was courteous but firm."

Chief Superintendent Adam Briggs said he had known Kennedy for more than 20 years and had always been impressed with his self-control. "He is someone who will defuse rather than wind up a situation," he said. Kennedy's actions had been "entirely reasonable and proportionate to what happened", he added.