A PROBATION officer's son who robbed a man at knifepoint while on early release from prison has been jailed for three years and three months.

Sean Drayton targeted the man because he wrongly believed he was a drug dealer.

He demanded he empty his pockets and took the man's bag, which only contained work stuff.

When police went to arrest the 42-year-old he turned on one of the officers and repeatedly punched him to the face.

Hannah Squire, prosecuting, told Swindon Crown Court the victim had gone to his girlfriend's house in Toothill after work on Wednesday October 7, but she was out.

He was talking to a neighbour when he saw Ashton Melhado, with whom he had words in the past as the man believed the victim had sold his cousin drugs.

Miss Squire said: "He returned to the bus stop, he felt uncomfortable seeing Ashton Melhado. He was looking at the timetable when he was approached by the defendant.

"The defendant said to him 'How long is the wait for the bus?', then without warning he went in to his tracksuit top and pulled out a knife which he brandished.

"He said 'I know you sell drugs, give me all your money'. He replied 'I don't sell drugs, I have been to work'."

As he continued to threaten the victim with the steak knife with a four or five inch blade he went to his pocket and pulled out some coins, handing over £4.50 in change.

After Drayton grabbed the money the man managed to push the attacker and as he went to flee, the defendant grabbed his bag containing work items and then he fled.

As he ran off he said to the victim he was going to 'nank' him, which is street slang for a knife him, and was then seen getting into a black car.

When the police arrived soon after they went to the vehicle, where Ashton Melhado was in the passenger seat and Drayton, who was by the door, ran off

PC Christopher Wilson was one of the officers giving chase and when he caught up with the knifeman he was punched in the face.

Drayton, of Alveston Close, Westlea, pleaded guilty to robbery and assaulting a police officer in the execution of his duty.

The court heard he had a long history of offending with previous for robbery, assault, burglary, theft witness intimidation and drug dealing.

As a result of the latest offences he has been recalled to serve the remainder of a three years nine month and a two-and-a-half year sentence for drugs offences.

Rob Ross, defending, said following his early release on licence in May last year he had stayed out of trouble until a shoplifting matter in the summer.

He said he thought the victim had drugs so he 'took a chance' but instead mad a serious error of judgement.

Jailing him Recorder Maria Lamb said "You are to be sentenced for a classic street robbery, you demanded money by knifepoint.

"Your gain, in fact, was miniscule though it is clear you hoped for more because you expressed the belief he was a drug dealer.