Only a year or two ago the Appeal Court decided that James Hanratty was guilty of the A6 murder on DNA evidence, when that murder was committed in 1961!
The problem is not the shelf-life of DNA but whether a proper chain-of-custody was observed at the time, so that there could be no possible cross contamination between one item of evidence and another. This means keeping those items in sterile bags or other containers from the very moment they are discovered.
Since DNA 'fingerprinting' had never been heard of in 1961 it is quite impossible for anyone to say, nearly 50 years later, that items of clothing and so on were not handled by the same people, put down on the same bench or kept in the same police-station cupboard.
So I for one cannot imagine what the Appeal Court was thinking.
Anyway, there is no 10-year expiry period for the validity of DNA