DNA evidence was used to convict Crawford

Mary Lynch died in hospital a week after being raped and assaulted on Christmas Eve 1987.

Crawford was convicted of the crime 12 years later after a DNA sample taken during a drugs raid on his home was found to match samples from the earlier crime scene.

Now it has emerged that his lawyers are set to challenge the conviction.

It is understood that they will point to the legislation on the use of DNA evidence.

They will insist that because the drugs charge against Crawford was dropped, it was unlawful for the Crown Office to use the DNA sample as evidence in the Mary Lynch trial.

DNA samples

Last year the Scottish Executive announced �1.7m of extra funding to allow police forces to increase DNA profiling and help build up a national database.

In March, Strathclyde Police announced plans to significantly increase the number of people who will be required to give DNA samples taken when arrested.

Only those arrested for serious crimes such as murder or rape were previously required to give samples.

But the force said it would increase the range of offences for which suspects can expect to have samples taken.