There are half a million break-ins in Britain each year and detectives need your help to track down some particularly active burglars. There's advice on how to make your home safer, and news of arrests and developments following last month's reconstructions. Nick, Sue and detectives from around the country are waiting for your call, to the Crimewatch studio.

Two months ago, a London car park attendant was shot dead. The officer who is investigating the murder believes it may have resulted from an armed robbery which went wrong. He is sure someone is shielding the killers. Since early February, four lorry loads of cigarettes have been hijacked in north London. On one occasion the gang was armed and so far half-a-million pounds worth of cigarettes have been stolen. As the cigarettes are sold viewers from anywhere might help solve the case.

Tonight police need your help again to find thieves who took dangerous firearms from a gun shop in the Midlands. In Hertfordshire, treasured watercolours were taken from a housewife by armed robbers posing as telephone engineers. And in south London, a private detective was brutally murdered after a drink in a pub. He worked all over the country; someone must know his killer.

There's news of five arrests following last month's programme and a detailed reconstruction of the strange, tragic case of Shani Warren. Thousands of Easter rail and road travellers might help piece together the events at Taplow Lake where Shani was murdered. And the hunt for the killer of 66-year-old Helen Fleet. Seven weeks after the fatal attack, near the seaside resort of Weston-super-Mare, detectives need your help.

This month viewers will be asked to help trace the man who posed as a housebuyer and assaulted a Sheffield woman in her own home. He may be responsible for attacks in other towns. And the last hours of Barry Oldham from Aberdeen. In May he went to Newcastle and visited a nightclub there. Next morning his body was found 60 miles away in North Yorkshire. With your help crucial clues about his death could help police solve the crime.

On tonight's programme, the murder of a north London jeweller. Christopher Comely was two days from selling up and moving away when he was shot dead. Several people saw the crime in which his guard dog was also fatally wounded. And in Newcastle-upon-Tyne the murder last month of 18-year-old Rachel Mewes. She may well have known her killer and police believe someone could be sheltering him.

On tonight's programme a series of rapes in the Notting Hill area of London that began in 1982. Despite publicity, the attacker was never traced. Now, after a four-year gap, the same man has committed two more rapes in the same area. Tiny but vital clues may prompt viewers to shed new light on his identity. In Newcastle upon Tyne, a wages hold-up at the Central Railway Station. The gang who used BR uniforms left a trail of clues dating back several weeks before the robbery. Wendy Knell was murdered in her home in Tunbridge Wells four months ago. Police are still looking for the mystery person for whom she bought antique model trains.

On 26 August, Rachel Partridge from Chinnor, Oxfordshire, was raped and murdered. Rachel's clothes, including her distinctive suede jacket, have never been found. Viewers may also help trace a mystery youth in 'gothic' dress seen near the barn when Rachel was found. Expensive cars stolen from West London by a man posing as a mechanic have reappeared in Spain and Morocco. But how did they get there and what were they used for? And from Hertfordshire, the bogus office cleaner and his partner who defrauded a bank of nearly a quarter of a million pounds.

News of arrests following last month's programme, and three major film reconstructions of serious crimes.