The Stagecoach bus was parked on Market Street on 7th May when Bernard Williams opened the rear door to the engine compartment and activated a cut-off switch.

Driver Derek Adam was checking out the power loss when Williams (18) pushed the door panel down onto the back of his head.

Only a short time earlier, Williams had been caught on camera as he took a life-size cardboard cut-out of a police officer out of Aldi store.

The cut-out, which was used as a police crime prevention display and valued at £130, was later found dumped and wrecked.

He later told officers he was 'dared' by a pal to steal the cut-out and was drunk at the time.

And Williams was in further trouble the following day when he ran out of Jaspers store carrying a 24-can crate of lager on his shoulder.

Williams, of Market Close, admitted two charges of theft and one of assault — and had no previous convictions.

The bench at Chesterfield Court adjourned sentence until 13th July for probation service reports while he is assessed for his suitability to receive an alcohol treatment programme.

In mitigation, Joe Harvey said: "Alcohol was a factor in all three offences. It was stolen from the shop for consumption.

"He and two friends will between them drink a bottle of vodka and 12 litres of cider in a day. He realises he could kill himself through cirrhosis of the liver if he doesn't do something about it now."