1. An mtDNA match is not conclusive in proving identity. A matching sequence offers only probabilistic evidence of identity or non-identity.
2. A difference in mtDNA sequences is not conclusive in proving that two samples come from different individuals.
3. Four unrelated individuals in the original British Caucasian Database of 100 have the same mtDNA sequences in the control region and other pairs of unrelated individuals are also identical.
4. At least 178 individuals in the total database of about 1000 individuals match at least one other unrelated person in the database.
5. The substitution or change rate for mtDNA is much higher than anticipated. This means that a higher number of cases, than originally expected, have been found and will be found where mother and child DO NOT match.
The use of mtDNA testing as the sole means of identification, must be stopped! At this stage, it's use as the primary evidence for identification is probably dangerous.
Here is some of what the scientific community has to say:
From Nature Genetics Volume 15 April 1997 ' "A high observed substitution rate in the human mitochondrial DNA Control Region" by Holland, Parsons et al. - "Our results have implications for the use of CR sequences in forensic identity testing, mtDNA is often employed to compare questioned samples to presumed maternal references. It is now clear that the mtDNA substitution rate is sufficiently high that differences between true maternal relatives will be encountered not infrequently, providing the grounds for false exclusion."
From Science Vol. 279 2 January 1998 - "...Parsons and Holland, in their work identifying 220 soldiers' remains from World War II to the present, now have new guidelines - adopted by the FBI as well - to account for a faster mutation rate. When a missing soldier's or criminal suspect's mtDNA comes up with a single difference from that of a relative or evidence at a crime scene, the scientists no longer call it a "mis-match." Instead the results are considered "inconclusive."
From New Scientist February 28th, 1998 - "Bearing False Witness Chance Matches Are Much More Likely with mtDNA Tests" - "A type of genetic fingerprinting with a high chance of producing a false match has helped convict six people in the US. The increasing use of this type of DNA evidence, based on DNA from the mitochondria (mt) of a cell, has sparked heated debate about whether it should be admissible in courts at all...."
"Because of these limitations, Britain's Forensic Science Service in Birmingham uses mt DNA only to eliminate suspects or to back up other pieces of evidence, Dave Werrett, director of research and DNA services at the FSS says it is vital that expert witnesses explain to the jury that a random match is far more likely with mt DNA. "What we do is put all the caveats up front."