The defence team in the trial of the man accused of raping and murdering Fleet teenager Marion Crofts 21 years ago have called into question DNA evidence.
Lawyers for Tony Jasinskyj claim procedures for collecting evidence from the Basingstoke Canal scene, where Marion's battered body was found, were not adequate for a positive DNA match.
Andrew Bright QC cast doubt on forensic evidence during his cross-examination of scene-of-crime officer Kenneth Paley a week into the trial at Winchester Crown Court.
Mr Paley admitted that at the time of Marion's death in June 1981, DNA matching was unheard of.
Former Army chef Jasinskyj, 45, from Leicester, denies raping and killing 14-year-old Marion of Basingbourne Close on June 6,1981.
The prosecution case centres on a DNA match between Jasinskyj and traces of semen found on Marion's clothing.
Mr Bright suggested that samples taken from the murder scene could have been contaminated.
Mr Paley said when he arrived at the crime scene in Laffan's Road, Aldershot, he found the area had been preserved and Marion's body had not been moved.
He said Pc Ian Webb gave him Marion's plimsoll, black sock and sponsorship form and he immediately put them into bags and labelled them.
After searching the outer area he went home at 8.30pm, washed and changed his clothes in order to attend another job.
At 9pm he went to Farnborough police station and placed the three items in the secure scene-of-crime office.
The next day he moved the items to Aldershot police station and received swab samples from Marion's clothing which he stored in the fridge.
In cross-examination Mr Bright asked: "When you began your career in 1970 the words DNA would have meant nothing to anyone?"
Mr Paley replied: "No."
Mr Bright continued: "This was a science that people knew nothing about. I think you will agree your job of scene of crimes undertook change from the point when DNA technology became advanced and it became a very important part of your job." Mr Paley agreed.
Mr Bright: "By the 80s although technology was not at an advanced stage, scene-of-crime exhibits had to be treated with very special care as they are capable of becoming contaminated as they come into contact with other DNA.
"We know that in attendance at the scene there were a total of three scene-of-crime officers and the approach to the exhibits between then and now is different.
"We know Pc Webb found the three items as he was first on the scene and handled them. We have heard in evidence that these items were placed on top of a police van."
When asked where they were when he arrived Mr Paley said they were handed to him by Pc Webb.
Mr Bright said the items would have been unbagged for 40 minutes and argued to the court that they could have been contaminated.
When detectives obtained a full DNA profile of Marion's killer in 1999 everyone involved in the initial investigation was asked to provide a DNA sample to eliminate them from inquiries, but Mr Paley initially refused.
He said he did not think it was necessary and that it was an infringement on his personal liberty.
He added he felt he was being treated as a suspect and he was informed that the DNA sample was from semen. However, he later provided a mouth swab for DNA testing.
The jury was told last week by prosecutor Michael Bowes QC that there was just a one-in-a-billion chance that semen found on Marion's clothes was not Jasinskyj's.
The case continues.