DNA evidence in the case of a man charged with the historic rape and murder of a teenage schoolgirl has been scrutinised in court.

Jurors in the case against Stephen Anthony Hough, who is charged with the rape and murder of Janet Commins in 1976, heard yesterday how forensic evidence was tested and kept following her death.

Hough, 58, of Maes Y Dre in Flint, denies charges of murder, rape and sexual assault – and an alternative charge of manslaughter.

During the second day of the trial, Dr Anthony Peabody, the now-retired forensic scientist who worked on the case, spoke of the process taken when analysing evidence from the scene.

The court heard Dr Peabody could not recall the case, and notes from his work had now been destroyed.

He explained he had to rely on a written police statement from the time to recall what work took place.

Dr Peabody received a number of items from pathologist Dr Rueben Woodcock and further items received later, the jury was told.

He spoke of how items would have been transported to the laboratory in a car boot with slides air dried “away from the action” within the morgue before being transported.

He said: “I would put them on the side away from where the action was and allow them to dry for a minute or two.

“Being aware of possible contamination, we would try to avoid any possible contamination.

“It would be well away from where anything was happening elsewhere.”

Dr Peabody was asked whether there was any possibility of cross- contamination having taken place in the process of preparing microscopic slides.

He said the possibility of “contamination by sperm” was “quite remote”, adding sperm cells did not float in the air.

He added slides were stored in a cellar after work had been carried out to examine the evidence.

Under cross-examination from defence barrister Patrick Harrington QC, Dr Peabody denied he had made a mistake in recording slides.

Mr Harrington questioned why a mouth swab taken by the pathologist was not recorded in a later report – and suggested it was a clerical error.

Dr Peabody denied that was the case and said if nothing of significance was found in the evidence, it might not be recorded.

He said: “This might not be what we would do now but, if there was nothing of significance, it would only be in my notes – but those are not available to me.”

When questioned how they could be sure the mouth swab had been tested, Dr Peabody said: “In 1976, you would have had to take my word.”

He added: “It is not a mistake. It is how things were done in 1976.”

Dr Peabody was also asked why intimate tests taken from Janet Commins after her death did not follow normal proceedure at the time?

He said he may have known at the time but, without the benefit of his notes, he was now unable to say.

Questions were also raised about the labelling of materials from this time, with Dr Peabody stating that the slides were kept in a slide tray, which would have had a case number on it.

He added: “In the space of 40 years, I have no idea how these have been stored, what has happened to them or what they were put into, but I would be very surprised if these slides were not in some way identifiable as coming from this case.”

The court also heard evidence from Dr Jonathan Whittacker, the forensic DNA expert who studied DNA tests taken after the case was reviewed in 2006.

The case was reopened by North Wales Police, who looked at whether there was any evidence against Michael Orford, who had previously been charged in connection with Janet’s death, with no evidence later presented.

He explained how work to analyse the material kept in the microscopic slides was carried out, before a DNA profile was entered into the DNA database.

The trial continues.