A young brother and sister's 'unsophisticated and ill planned' attempt at snatching a shop's Christmas takings ended in a rooftop chase through Slough - and a prison sentence.

Marcel Carpenter, 20 and his sister Keonie, 18, of Moray Drive, Slough had both pleaded guilty to a charge of robbery when they appeared at Reading Crown Court on Friday. Miss Carpenter had also admitted a charge of assault by beating.

The failed cash grab happened at Slough's Queensmere Observatory Shopping Centre on December 27.

The court heard how Keonie Carpenter had worked at the Blue Inc clothes shop in the centre until February last year and knew details about how the shop's takings were taken to the bank nearby.

Shortly before 10am the day after Boxing Day an employee at Blue Inc left the shop, carrying a bag with more then £5,500 worth of Christmas takings. Marcel Carpenter grabbed the bag and tried to run for it.

But his victim and the store's manager gave chase, joined by eight to 10 others.

Carpenter was chased through the High Street, down an alley, up some metal steps to the roof of Starbucks and down into the car park where he threatened the store manager with a pair of scissors before being detained.

His sister had tried to block the store manager's way as he led the chase, shouting 'you can't grab him like that' as her brother was detained and hitting the store manager on the back of the head.

Steven Pidcock, defending Marcel Carpenter, said his client had been depressed because he did not have the money to buy Christmas presents for his family or friends at Christmas.

He said: "This was a stupid mistake not carefully planned – a young man exhibiting poor thinking skills and poor problem solving skills.

"He has very low self esteem and wanted to treat his friends and family the way they had treated him.

"He has had five weeks in custody and it has been a salutory lesson. He misses his mother and his sister."

Mariska Van Leeuwen, defending Kenoe Carpneter, said she was deeply remorseful.

Judge Paul Dugdale described the sibling's crime as a 'very, very stupid escapade'.

He said: "People who work in business and have to carry money deserve the protection of the court."

He imposed a two year sentence - half of it to be spent in prison.