DNA Error or DNA Success?

Sean Hodgson was recently freed after 27 years in prison for a murder he did not committ. This was not a case of the police knowing they had the right man and a technicality getting the individual of, but rather a case of a innocent man being freed, thanks (in part) to DNA testing.

DNA, which is often used to prove a conviction, showed that the Sean Hodgson was innocent, and the judge stated that it was not possible for Sean to have committed the crime.

The reasons Sean went to prison are no longer relevant as the UK police force’s  and laws have change beyond  all recognition since the original case in 1982 (the major change being the introduction of the Police and Criminal Evidence Act 1984, enacted in 1986).

What is relevant to the UK, and this site, is the reasons Sean was not freed adecade ago.

11 years ago the FSS, Forensics Scientific Service, conducted a review of the case and told the defense team that the that case exhibits had not been retained, when in fact they had. It is these same case exhibits that resulted in the freeing of Mr Hodgson in 2009.

Since the  revelation of this failure by the FSS,  which resulted in the an additional 11 years behind bars for Mr Hodgson, it has emergeged that there is an intent to sue the Forensic Scientific Service by the lawyers for Mr Hodgson.

It is the error over a decade ago, which poses the major concern now. Exhibits were booked in, lost, believed to be destroyed and then found again.

Due to the sheer volume of exhibits and data that the FSS handle, this is not in the least bit surprising; errors happen.

There is no suggestion that the error was malicious, or part of a cover up, mearly an error. But this is the problem with DNA sampling, its belived to be infalliable, but people  make mistakes, in labelling, sampling, and even following procedures.

This will always happen, its happened before, and will happen again, in fact DNA errors are more common than people may think. In addition to this there can be errors in the DNA databases itself, and errors can be made during the collection.

Therefore at every point in the DNA testing chain of evidence, from collection, sampling/comparison, and storing there can be, and will be, errors.

In this case an error with the DNA system failed to free a man, though equally an error could put an innocent behind bars. Though it should be remembered that the same system that failed to free Sean Hodgson, was later used to prove his innocence.

Due to the statistical errors involved in DNA comparison (collection, testing, storing) the more DNA tests that are carried out the more errors there will be, and this can not be avoided.

With the UK databases having grown so much in the past decade, there are questions as to how many other errors have occured. With the recent S and Marper v United Kingdom ruling, it means that less DNA should be taken, though this does not seem to have happened, but if it does, the potentail for accidental errors will decrease.

Though the potentail for deliberate errors will remain the same.

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