A teenage robber who used Gumtree to choose his victim, has been sentenced to two years in a young offenders institute.

The 17-year-old who cannot be named, was dubbed the 'Gumtree robber' by investigating officers, after trawling the site to identify his victim, who was selling two items of jewellery each valued at around £500.

Croydon Crown Court heard the teen contacted the victim using a mobile phone and arranged to meet him at Ampere Way tram stop, to purchase the items at about 6.30pm on July 8, 2011.

The victim and a friend, both 22, went to the tram stop to meet the suspect but remained in a car.

They were approached by the teen and another male who looked at the ring, but when the victim became suspicious the suspect reached into his waistband and pulled out what the victim believed to be a gun.

The victim drove away and contacted police shortly afterwards to report the incident.

Officers conducted a search of the area with the victims, but were unable to locate the two suspects.

An analysis of phone and internet usage led officers to an address in Croydon on July 28, where they arrested the suspect just after he had finished a driving test.

A search of the property uncovered the phones and computer used to coordinate the crime. An imitation firearm was also recovered from the address.

The teen later pleaded guilty to charges of attempted robbery and possession of an imitation firearm with intent to commit an indictable offence.

DC David Huzzey, from Croydon's Robbery Squad said: "Through phone and IT investigations we were able to identify the main suspect in this case and after the search of his home address it was clear we'd found the person responsible.

"He made no comment throughout his interviews, but given the weight of the evidence against him, pleaded guilty to the offences."

The second suspect in the case is still to be identified.

Anyone with information should contact Croydon's Robbery Squad on 0208 649 1334 or call Crimestoppers anonymously on 0800 555 111.