This feature was first published in May 2024 in My Mensa Weekly, our exclusive newsletter for Mensa members. Find out more about becoming a Mensa member here.

Words: Joanna Cummings

As a nation, we are hooked on crime: true and fictional, on TV or via podcasts – as an example, crime is the most popular genre of fiction in the UK, with 40% of book buyers saying that they read crimes and thrillers. And a crucial part of the appeal (beyond an occasionally lurid fascination with the crime itself) is the detectives who tackle the cases, the clever figures who apply their powers of deduction to catch the perpetrator. 

Whether it’s the logical reasoning of Sherlock Holmes, Jessica Fletcher’s eye for detail, or the dogged determination of Vera Stanhope, we are fascinated by their methods of piecing together the evidence and solving the case.

Of course, the work of real-life detectives is a different story. To be a good detective requires a unique blend of analytical skills, attention to detail, good communication, technological proficiency, legal knowledge and – since crime-solving can be both tedious and stressful – considerable mental and physical stamina. Compared to the high drama and rapid progress on screens and in books, a detective’s work is likely to be much more mundane, relying on meticulous investigation through teamwork and, of course, sticking to the rules (something often neglected by our favourite fictional crime solvers).

First let’s consider the initial response to a crime. Patrol officers tend to be first on the scene and are responsible for securing the scene to protect potential evidence. It is usually later on that detectives arrive, conducting their initial survey and talking to witnesses. Rather than the ‘whistlestop’ tour of the crime scene depicted on our screens, this part of the investigation is painstaking and takes considerable time, setting the stage for the entire investigation.

The collection and analysis of evidence is not as speedy or as clear-cut as you may think. The forensics team is required to photograph the scene, take measurements, collect evidence such as fingerprints, DNA, weapons and any other potentially important materials – a rigorous and time-consuming undertaking. The forensic analysis of findings can take weeks, or even months, with contamination a real issue – and in many cases, specialists need to know what to look for. No magic tool yielding instant results here!

And as for the suspects… Many of us would like to think that detectives really ‘grill’ potential criminals, amping up the pressure to eke out their confession. In reality, while interrogation takes considerable expertise, requiring good interpersonal skills and the ability to ask the right questions at the right time, considerable care needs to be taken to respect the rights of interviewees and stick to legal procedures. Detectives need to be careful about obtaining false confessions or being accused of manipulation; they work closely with prosecutors to build their case and make sure any testimony stands up in court.

None of this is to say that the famous ‘detective’s hunch’ doesn’t have a role to play. While it may not be a substitute for concrete evidence, intuition – which is essentially guesses based on knowledge and experience – can help a detective decide where to focus within the investigation, who to question, or when to revisit a particular lead. Psychology plays a key role here too; an understanding of human behaviour is important whether dealing with criminals, victims or members of the crime-solving team. However, the real skill comes from backing up this awareness with solid investigative work – not Miss Marple’s wheelhouse, perhaps.

So, while we might all love the drama of detective work depicted in the media, the truth is a little less glamorous. To build a case and get it to court, a truly great detective balances the rational, the scientific, the legal and the interpersonal in a relentless and thorough pursuit of evidence. While this might make for much slower progress (and less compelling viewing if it were dramatised), it should certainly give us a greater appreciation for those who tackle this role on a day-to-day basis – after all, it is this methodical approach that protects us, and is more likely to bring us justice.

A day in the life of a detective

Want to know more about what it’s really like? Caroline Anderson of the South Yorkshire Police shares stories and advice.