DETECTIVES from all over the country are today meeting in Essex to probe similarities between a series of murders.

Files on three local unsolved murders are believed to among the 220 cases being analysed as part of operation Enigma.

There is speculation that some of the murders could be the work of a number of serial killers still on the loose or already jailed.

Mr James Dickinson, Assistant Chief Constable of Essex police who is co-ordinating the study, said the high level meeting "is a study group to look at our facilities, methods and ways we can improve them."

Police will collate and analyse relevant information regarding the victim, the Crime and any suspects from a number of detected and undetected cases. Local unsolved murders include:

Manchester-based prostitute Maria Requena who was found dead at Pennington Flash, Leigh in 1990.

Liverpool prostitute Linda Donaldson whose body was dumped at Lowton in 1988.

Grandmother Shirley Leach who was murdered in the toilets at Bury bus station.

Police say no definite links have so far been established between any of the murders nationwide but there has been speculation that some could be the work of the same men, including convicted killers such as the Yorkshire Ripper. Mr Dickenson will be working with the National Crime Intelligence Service, the Forensic Science Service, the Police Research Group from the Home Office and academics from the Police staff college.

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