Unsolved English murders

In the United Kingdom, there are a number of unsolved murders. In the past thirty years numerous children have disappeared or been found dead, with no known suspects for the deaths:

Christine Markham, 9, missing from Scunthorpe 1973
Lesley Molseed, 11, disappeared in 1975 within a few minutes, from a country lane in Delamere Road, Rochdale, and her body was found three days later on open moorland above the A672 Oldham to Halifax Road in Ripponden, West Yorkshire.
Genette Tate, 13, missing from Aylesbeare, in Devon, on August 19, 1978
Sean McGaun, 15, murdered on April 7, 1979
Suzanne Lawrence, missing in Essex, 1979
Martin Allen, 15, vanished from central London on November 5, 1979
Marion Crofts, 14, murdered at Fleet, in Hampshire, on June 9, 1981
Vishal Mehrota, 8, murdered in Putney, West London, on July 29, 1981
Jason Swift, 14, murdered in Hackney, East London, on July 11, 1983
Imran Vohra, 9, killed the same afternoon at Preston, in Lancashire
Colette Aram, 16, murdered at Keyworth, in Nottinghamshire, on October 30, 1983
Lynda Mann, 15, killed in Narborough, Leicestershire, on November 21, 1983
Chris Laverack, 9, murdered in Hull on March 9, 1984
Mark Tildesley, 7, vanished from Workingham, Berkshire, on June 1, 1984
Patsy Morris, 14, missing in 1990
Barry Lewis, 6, murdered in Walworth, South London, on September 15, 1984
Marion Crofts 1990
Lisa Hession 1990

In all these cases no suspect has been positively identified, and each investigation has now stalled.