Northampton family murder suspect 'changes identity'
Police investigating the Ding family murders in Northampton believe key suspect Anxiang Du may have changed his identity or changed his appearance.
Jifeng Ding, his wife Helen and their two daughters were found stabbed to death at their Wootton home in April.
Det Supt Glyn Timmins said he believed Mr Du, 52, from Coventry, was "hiding within the community in London".
"I think somebody has got to be assisting him, after all this time," he said.
CCTV images have been released showing Mr Du, 52, from Coventry, at Northampton Bus Station at 1250 BST on the day of the murder.
On Friday it was revealed that a 999 call believed to have been made as the family was being murdered was being investigated by the police watchdog.
Northamptonshire Police said it had referred the response to an abandoned 999 call on 29 April to the Independent Police Complaints Commission.
Police believe Mr Ding, a lecturer at Manchester Metropolitan University, his wife and the children, Alice, 12, and Xing, 18, were killed on 29 April. Their bodies were found two days later.
The investigation moved to London last week when the missing family's Vauxhall Corsa hire car was found in St John's Wood.
Crimestoppers has put up a £10,000 reward to find the person responsible for murdering the family.
The case is due to be featured on the BBC's Crimewatch programme on 24 May.