A serial shop robber who threatened a teenage girl at knifepoint has been jailed for six years.

John Coyle attempted to rob a Scotmid store in Easterhouse, Glasgow, by threatening to stab the 18-year-old shop assistant.

After asking the girl for a packet of cigarettes he produced the large black-handled knife and thrust it towards her stomach demanding she opened the till.

But the 44-year-old, who was caught because of a distinctive grey streak in his hair, fled empty handed after the teenager screamed and shouted for her mum who was also an employee there.

Coyle was also ordered to be monitored in the community for eight years after his release because of his high risk of re-offending.

The incident, which took place in October last year, was captured on the shop's CCTV.

At the High Court in Glasgow on Monday officers told how they recognised Coyle from Cranhill, Glasgow, after viewing the footage which showed his "very distinctive" grey streak.

The court also heard that he had already served a number of lengthy jail-terms for similar crimes and had been released on licence 11 months earlier.

He had been freed early at the time having been locked up for almost eight years in 2009.

On handing down the sentence Lord Burns ruled that Coyle will have to serve the unexpired four-year portion of his previous sentence before starting his new sentence.

Defence counsel Geoffrey Forbes said: "He feels shame and disgust at his conduct and would like to apologise to the shop assistant."