Roy Tutill

The National DNA Database (NDNAD) and advances in forensic science techniques were crucial in helping to find the killer of a schoolboy murdered more than 30 years ago.

Roy Tutill went missing after hitching a lift home from school in Surrey in April 1968. Three days later the 14-year-old's body was found in woodland near Leatherhead. He had been sexually assaulted and strangled.

Medical samples and Roy's clothing were examined but blood group testing failed to give any satisfactory results.

In 1991 swabs from the victim were re-examined and single locus profiling was carried out on his trousers. On this occasion the technique failed to give a result but semen stain samples were extracted and kept in the freezer.

The first breakthrough came in 1996 when SGM profiling was used and a DNA profile was obtained from an extract of the medical swab and loaded onto the NDNAD.

In 1999 Brian Lunn Field from Solihull, West Midlands, was stopped by police on a drink-driving offence. A routine DNA buccal swab was taken and his profile was loaded on to the NDNAD which gave a match against the 1968 crime scene stain.

A year later the murder investigation was reopened by Surrey Police because of the new forensic evidence.

Further re-testing on the swab extracts using FSS SGMplus™ achieved a partial DNA profile with a match probability of one in 20 million. Field was then arrested and charged. Further work done on samples from the trousers that had been kept in the freezers gave a full DNA profile that matched Field.

Field denied the charges at his first court appearance but pleaded guilty to murder when he appeared at the Old Bailey in November 2001.

Sentencing him to life imprisonment Judge Gerald Gordon said: "Advances in modern science techniques should stand as a warning that there is no hiding place for sexual and violent criminals."