Hi KG1 - yes, that one from 2006 is the technique that I'd heard about a few years ago, using RNA degradation. I don't know that it ever went anywhere or fulfilled its promise.
I asked one of my contacts today about the ageing of blood stains, and it is still, apparently, highly unreliable. I have also emailed another contact in the UK for more information from the point of view of the Police Scientific Service, but so far haven't heard back. One of the questions I asked was whether or not the results of any testing were admissible in court.
Incidentally, it should be noted that a lot of the laboratory forensic testing here is done by the Police Scientific Service in their own labs, while the forensic pathology is carried out by the Forensic and Scientific Services (FSS) on the campus of Griffith University. Two separate institutions. The FSS is the one that used to be called the John Tonge Centre - but actually hasn't been called that officially now for several years.
If I hear back from the UK re the lab testing of blood stains to determine their age, I'll post the answer.
And of course I'm talking about stains more than a couple of hours old - that first 2-3 hours has certain changes in the form of coagulation and the formation of fibrin, etc etc (it gets complicated) that can give a pretty good idea of the age. But once that stage has passed, I'm not sure that stains - especially when "rubbed in" to material like a carpet, car lining material, etc can be aged accurately.