Frank Taylor, Chief Constable of Durham, giving evidence to the House of Lords committee on forensic science, said forces were caused 'tremendous difficulties' by the delays - on samples such as blood, fibre, semen and drugs.
'A quick result can eliminate certain lines of inquiry and save resources; evidence goes stale lying around the laboratory . . . yet a quick result can have major implications for the policy and development of an inquiry,' he said. Lord Dainton, the committee chairman added: 'Evidence delayed is evidence denied.'
The committee was told that since the change of the Forensic Science Service to an agency - floated away from the Home Office - many scientists had left and many senior people were now tied down by administration; the result was a smaller number of scientists were doing less work and charging more to the police.
Mr Taylor, who was giving evidence on behalf of the Association of Chief Police Officers, said the morale of the service was 'extremely low' but the quality of their work was not open to criticism. Chief constables were apprehensive about going elsewhere for tests, but as charges rose were often faced with a choice of limiting samples or going back to police authorities and asking for more money.
Professor Michael Green, a Home Office pathologist and head of the department of forensic pathology at Sheffield University, said some toxicology samples were taking between 12 and 15 weeks to analyse by the forensic science laboratory at Chorley, while the same quality results could be obtained elsewhere within 24 to 36 hours.
The committee is due to release its report next spring.Reuse content