The over-reliance by police and governments on DNA fingerprinting is discussed: 'the use of DNA evidence in criminal cases, in particular the use of so-called cold hits to identify perpetrators, is worrisome.
This technique involves attempting to match a DNA profile obtained from a crime scene against a DNA database. Police forces across the world claim that this technique has allowed them to solve many cases, some years old.
In New York City police are going one step further. To prevent sex-offenders from using the statute of limitations to escape prosecution, where no match can be made to a person, the DNA itself will be charged with the offence. But this approach ignores the fundamental reason for a statute of limitations-in very old cases it is hard for defendants to defend themselves properly.'
The matching of an individual's DNA to that of DNA recovered from a crime scene does not necessarily mean that that person is the criminal: 'First, a DNA profile can be generated from very few cells that can be left by innocent means-the amount left on a drinking glass or a door handle. Second, although the number of DNA repeats used to compare profiles means it is very unlikely that any two individuals will have the same profile, it is not impossible. Third, at least in the USA, the standard of work in many laboratories that handle DNA evidence is not consistent; despite several cases where laboratories mishandled DNA evidence only three states, New York, Oklahoma, and Texas require accreditation to specified standards.'