Daniel Sandford walked up to Kevin Fish, who suffers from mental health problems, outside his home and headbutted him.

The yob then punched the 49-year-old in the face and snatched his bag from his hands.

After stealing bank cards from the bag, he told Mr Fish: 'If you touch me, I will beat you up. I know where you live.'

The victim called 999 when Sandford ran away from the scene of the robbery in Malins Road, Buckland, Portsmouth, on July 21 last year.

Police caught up with him nearby and when they searched his home they found some of Mr Fish's possessions.

At Portsmouth Crown Court Sandford was jailed for three years.

Sandford, who had been celebrating his 21st birthday on the day of the robbery, has been in and out of prison on several occasions.

In September 2003, he was jailed for 18 months for robbery.

And in July 2005, Sandford was sent to a young offenders' institution for two years after attacking a man and stealing his mobile phone.

Sandford, of Nelson Court, Buckland, Portsmouth, showed little emotion as he was jailed for three years after admitting robbery.

Judge Richard Price said: 'This is a case of street robbery on someone you knew.

'You headbutted him, punched him and pulled his bag off him.'

Sandford's friend Oliver Sharpe, who had asked Mr Fish for his PIN so he could withdraw £30, also admitted handling stolen goods in relation to the offence.

The 19-year-old, of All Saints Road, Portsmouth, was given a 26-week prison sentence suspended for two years and told to complete 60 hours of unpaid work for the community.

He was also made the subject of a six-month curfew order.

simon.jones@thenews.co.uk