Forensic Evidence Mishandling Derails Justice in Thousands of UK Cases

By: Shane Lambert
Time of writing: June 16th, 2025

Systemic Crisis in UK Forensic Evidence Handling

A BBC News investigation revealed a systemic crisis in England and Wales, where over 30,000 criminal prosecutions have collapsed in the past four years due to lost, damaged, or contaminated police evidence. Sima Kotecha wrote an article earlier this month on the topic at BBC.com (June 6th, 2025).

"More than 30,000 prosecutions in England and Wales collapsed between October 2020 and September 2024, data from the Crown Prosecution Service (CPS) reveals. They include 70 homicides and more than 550 sexual offences."

Featured eBook: Forensics: What Bugs, Burns, Prints, DNA, and More Tell Us About Crime by Val McDermid

Dive into the world of forensic science with Val McDermid’s Forensics: What Bugs, Burns, Prints, DNA, and More Tell Us About Crime. This engaging eBook explores how forensic techniques solve mysteries, including missing persons cases, through expert insights and real-world examples.

Perfect for true crime fans, it’s available on Amazon: Buy it here.

I do receive a commission from qualifying sales through Amazon's affiliate program.

The issue has profoundly affected cases involving missing persons, violent crimes, and other serious offenses, leaving families without answers and justice delayed or denied. The report points to the 2012 closure of the Forensic Science Service (FSS), a centralized body for forensic analysis, as a key contributor to these failures. Since its dissolution, police forces have relied on private forensic providers and their own storage systems, resulting in widespread mishandling of critical evidence.

Impact and Proposed Reforms

The FSS’s closure, driven by budget cuts, forced police to outsource forensic work or manage evidence internally, often with inadequate resources. This has led to significant errors, such as evidence being misplaced, contaminated, or improperly stored, rendering it useless in court. 

Contamination of evidence poses an additional severe risk, where even minor mishandling—such as cross-contamination from unsterilized tools or improper storage—can introduce foreign DNA or degrade samples, leading to inconclusive results.

In extreme cases, such as serial killer investigations, contaminated evidence could obscure critical links between crimes, potentially allowing a perpetrator to remain at large. Historical examples, like the misidentification issues in the early days of DNA analysis, suggest this is a plausible outcome when forensic standards falter, especially given the current disorganized state of evidence management in the UK.

Furthermore, the legal standard of reasonable doubt works in favor of the defense. In the case that someone is guilty, the prosecution still must prove it convincingly. Any kind of mishandling of evidence works in favor or the defense to obtain an acquittal because it can help establish reasonable doubt.

Freedom of Information requests uncovered the scale of the problem, with thousands of cases—ranging from sexual assaults to homicides—dropped due to evidence issues. In some instances, police lost critical items like clothing or biological samples that could have linked suspects to crimes or identified remains. Other cases saw evidence degraded due to poor storage, making forensic analysis impossible. These failures not only derail prosecutions but also undermine public confidence in the criminal justice system, as victims and families are left without resolution.

The Law Commission has responded with a consultation proposing the re-establishment of a national forensic service to standardize evidence handling and improve accountability. The consultation also suggests criminalizing deliberate evidence mishandling in severe cases, a measure backed by legal experts to deter negligence. This proposal is expected to reach Parliament, offering hope for reforming a system plagued by chaos since the FSS’s closure. The crisis highlights the fragility of forensic processes and their critical role in delivering justice, particularly in complex cases like those involving missing persons.

The scale of this issue calls for urgent reform to ensure evidence is preserved and handled with the care needed to solve crimes and bring closure to affected families. As the UK grapples with these challenges, the need for robust forensic systems has never been clearer.