A man has been jailed for four years for one count of robbery and given another four years to run concurrently for two attempted robberies in Milton Keynes.
Jamie Aldridge, aged 21, of no fixed abode, was arrested on April 24 on suspicion of robbery.
The arrest was in connection with an incident in the High Street and Clay Hill where Aldridge was arrested after approaching a group of three teenagers with a dog.
Aldridge then made threats to the victims and a mobile phone was stolen.
Aldridge was sentenced at Aylesbury Crown Court on August 12.
DC Suffling said: “This is a particularly nasty robbery on three innocent teenagers who were simply playing football in the park – something they should be able to do in their local area without fear of being subject to threats and having property stolen.
“This sentence imposed by the court sends out a strong message that this type of crime will not be tolerated in Milton Keynes or anywhere else in the Thames Valley.”