Peter Sullivan and DNA Evidence – The Power to Exonerate

DNA evidence has been part of the forensic toolkit for around 40 years and has been at the heart of cold case and post-conviction review for the best part of two decades. Advancements over time have improved discrimination, sensitivity, stability and utility of routine methods, and the addition of specialist techniques, such as the male specific Y-STR profiling method (see this article for background) and advanced probabilistic genotyping software (used for assessment of complex mixed DNA profiles), have expanded the reach of what has always been a very powerful tool.  What this means today is that evidence that would have been inaccessible in the past may no longer be so.

Making A Difference

The recent high-profile acquittal of Peter Sullivan, a man wrongfully convicted of raping and murdering Diane Sindall in 1986, shines yet another spotlight on the potential for modern DNA profiling methods to progress investigations into historic crimes.  This time, it was Y-STR profiling that provided the breakthrough findings and ended Mr Sullivan’s 38 year ordeal.

This shocking miscarriage of justice would be easy to discount as a one-off – but this is just the latest of a string of high-profile acquittals off the back of DNA evidence. In 2013, Victor Nealon’s conviction for attempted rape was overturned after 17 years in prison, and in 2023, Andrew Malkinson’s convictions for rape and assault were overturned after spending 17 years in prison. In each case, further analysis identified DNA that pointed away from the defendants. Peter Sullivan, Andrew Malkinson and Victor Nealon spent a total of over 70 years wrongly imprisoned before DNA evidence set them free.

The Challenge of Historic Cases

The challenge when working with historic cases is of course access to items or materials of evidential value. Whilst in all but the most recent of cases exhibits will likely have been destroyed, it is common, and even more so for older cases, for materials generated during original examinations to have been retained.  Whilst some of these, such as DNA extracts relating to previous attempts at DNA profiling and microscope slides made from body swab extracts, will be obvious targets for DNA profiling, others may be less so: for example adhesive tape lifts used to recover fibres and test papers used to locate biological staining (which used to be dried and held on the case file) – each of which has the potential to have picked up and preserved evidentially useful DNA from the original exhibit.

So what should you do if a serving prisoner approaches you and says they’ve been wrongfully convicted?  Firstly, determine whether the case is likely to have involved the transfer of bodily fluids; if not, it’s still probably unlikely that advances in DNA methodology will assist.  Secondly, establish what materials have been retained, noting here that some may be ‘hidden’ within case files, and get them, or details of them, to a suitably qualified forensic scientist so they can consider and strategize examinations and testing.  Thirdly, don’t be dissuaded if a review has been conducted previously; as Mr Sullivan’s cases aptly demonstrates, technological advances over time can change the position on what is and isn’t possible.

Conclusions

• DNA technology continues to develop, making it a key part of any post-conviction review, as recent acquittal demonstrate.

• A forensic scientist must be involved in setting the review strategy, to ensure the latest developments are considered.  

• Retained materials need not include original exhibits, but will require something that captured biological material during the original examinations.

Keith Borer Consultants employs a team of forensic biologists with extensive experience of operating within criminal justice system; including on high profile post-conviction reviews, such as the Andrew Malkinson and Victor Nealon cases .  If you have a case that you feel warrants further, independent review we would be more than happy to help.