Low copy number DNA (Deoxy-riboNucleic Acid) testing was one of the key planks of the failed prosecution case against Sean Hoey. Mr Justice Weir made it clear he was unhappy with the LCN DNA evidence.
Scientists believe they can obtain a good LCN DNA evidential profile from as few as 10 or 20 individual cells, which could be microscopic traces.
DNA is extracted from such traces, usually by dissolving any cellular material off the carrier and into a neutral solvent.
Chemical systems have been developed that can increase the sample size to try to enable scientists to obtain accurate readings from these tiny samples.
Absolute cleanliness to avoid contamination is vital to ensure the validity of this evidence.
The judge made some minor allowance for the fact that the DNA evidence was extracted from evidence that related to 1998, a period before huge advances in DNA testing.
However, he complained about the "cavalier disregard" by police for the integrity of the items of evidence, including those that related to LCN DNA.
"I find that that DNA evidence . . . cannot satisfy me either beyond a reasonable doubt or to any other acceptable standard," he said in relation to the DNA evidence against Mr Hoey.
According to the defence, as cited by Mr Justice Weir, outside Britain LCN DNA has been adopted for evidential purposes in only the Netherlands and New Zealand.
The judge's demolition of the DNA evidence could raise questions about its wider use.