An unlucky Singaporean thief picked up six years of hard labor after the unique(独特的)ring of the mobile phone he stole led police straight to him. Pretending to be a police detective, Rahman Magundario robbed two teenagers in a park, told them to turn their backs and stole the $140 phone, court documents show. If he had chosen another target(目标)in the mobile mad city state, he might have got off the hook. His number was up a short while later when the victim(受害人) heard the characteristic tune he had programmed into the phone. An unsuspecting buyer, who paid $ 70 in a coffee shop for what he thought was Magundario's mobile, pointed the thief to the police. The 39-year-old was sentenced for threatening the teenagers and pretending a police officer. 'He got six years of corrective training,' a court official said. 'It's worse than a prison sentence.' It can be learned from the text that Magundario ______.