Why worry about fingerprints when you can use DNA. Scientists tell us that every person's DNA is unique, so here we have an infallible way of proving identity and family relationships!

Except that the more science knows about this grossly immature disipline of DNA, the more it discovers that infallibility is not guarenteed. There are now witnessed cases of women giving birth to children whose DNA does not match the mother's - a godsend to the mother who was accused of stealing her children from other families. Given another 20 to 50 years for this disipline to mature and I reckon we will know about a whole load of other oddities about DNA that will have to be taken into account by any system that uses DNA to 'prove' identidy.