Robert Knowles, 68, is a serial shoplifter who has clocked up nearly 350 offences since 1959 . Britain's most persistent crook with a criminal career spanning 50 years has been jailed again after his 190th court appearance. Robert Knowles, 68, from Plymouth, Devon, is a serial shoplifter who first broke the law when he was 13 and has been in court at least once a year since 1959. The pensioner has broken the law so many times that prosecutors have lost track of his expansive record, which includes 200 thefts and dozens more for other dishonest offences. It is believed Knowles has now clocked up in the region of 350 offences over his lifetime. He pleaded guilty to stealing a watch and a pair of cuff links worth £50 from H Samuel in the city centre at Plymouth Magistrates Court in his most recent offence and jailed for 16 weeks. The court heard he had only recently been released from a six week jail sentence imposed by the same court and was told he must pay an £80 victim surcharge. Knowles, who has spent most of his adult life in prison, had been living briefly in a hostel in Plymouth before the thefts on March 14. Defence lawyers say the pensioner only goes between 24 and 72 hours before he is rearrested after each court appearance. 'Nobody knows why he does it,' his long-term solicitor Alan Harris said. 'Nobody knows whether he is effectively waiting to die in prison.' At a previous court hearing, Mr Harris told magistrates Knowles is an alcoholic who 'recognises himself as institutionalised' and steals to go back to jail. In 2013 he was caught stealing two boxes of chocolate from Thorntons but despite eating the £13 chocolates in the street, a security guard let him off with a warning. He then went to a nearby Tesco Metro and walked out with £26 of food - prompting staff to call police. And in 2011, Knowles admitted stealing two bottles of whiskey, watches and socks worth £279 from Marks and Spencer. During that hearing at the same court, Mr Harris said: ‘He can cope very easily with prison but cannot cope very well with the world outside. 'This is as bleak a plea and mitigation as this court can ever wish to hear.’ Knowles left prison six months later and committed another shoplifting offence within a week, this time stealing a watch, sunglasses, underwear and socks worth £79. He pleaded guilty to stealing a watch and a pair of cuff links worth £50 from H Samuel in the city centre at Plymouth Magistrates Court in his most recent offence and jailed for 16 weeks . The Crown Prosecution Service cannot give a full breakdown of his offences because so many of them they pre-date its creation in 1986. Knowles, who was sent to a correctional school in 1959, has been one of several criminals to win the dubious honour of being named 'Britain's most prolific thief'. Those with an even worse record include Bolton kleptomaniac Harry Hankinson, 64 - who in June blamed his 501 crimes on a blow to the head in 1970 which changed his personality. And in March David Archer, from Prestatyn, North Wales, clocked up his 343rd offence - just edging out competition from Knowles.
Robert Knowles, 68, from Plymouth, first broke the law when he was just 13 . He was jailed for 16 weeks for stealing  watch and cuff links in recent crime . Pensioner has broken law so many times prosecutors lost track of record . Knowles has now clocked up nearly 350 offences in his lifetime .