Inside The Mind of A Detective: What Skills Do You Need?

Have you ever dreamed of becoming a detective? Do stories about Sherlock Holmes, Hercule Poirot and maybe even Ice-T from Law & Order SVU make you wonder if you have what it takes?

We spoke to two former detectives to find out what skills a detective needs. Duncan McNab is a former detective and private investigator turned journalist and true crime author. His latest book Roger Rogerson was released in late 2016.

Belinda Neil is a former police detective, homicide investigator and hostage negotiator. She is also the author of the best-selling memoir, Under Siege and an inspirational speaker.

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‘Hard’ is an understatement when it comes to being a detective. You have to be dedicated and truly want to do the job.

“I’m appalling nosey and inquisitive,” laughs Duncan McNab. “I like to find out everything I can. I’m always intrigued by things I want to know. To be a detective, whether it’s in the police force or private practice, you really have to want to find things out. You get up in the morning and the first thing you think about is where the day’s adventure is going to take you.”

He continues, “Really good detectives are utterly passionate about it. They give a damn and don’t give up. They’ll fight.”

“You talk to coppers who retired 10 or 15 years ago and they still carry with them that passion to see justice on a case they have ever been able to fully resolve.”

Gut Instinct

Some call it gut instinct or a sixth sense. Others, simply the ability to read a scene. No matter what name you give it, it’s imperative to detective work.

McNab explains, “Good coppers who know their business and have the right skills and experience gain instinct. They can look at a crime and think [that] the likelihood of X being responsible is pretty good.

“What you don’t do is then try and build your evidence to support what you think. Let the evidence take you there.”

Neil agrees with this. “Gut instinct is very important but you can’t ever completely rely on it. It’s another [arrow] in our quiver, so to speak.”

“You might have a gut instinct about a particular person…but again it’s always imperative to review evidence and facts.”

McNab also details how even the most seasoned professionals can sometimes get it wrong. “Older, more experienced investigators can walk into a room and just smell if things are going to get interesting. You walk in and you know if there’s a problem.”

“On other occasions you might be meeting with someone you’re terribly apprehensive about, they might be a serious crim, and you walk out thinking, ‘That was quite pleasant actually. Nice fella! Sure he’s a terrible crook, but he’s not all that bad!’”

“I met a contract assassin once who was very pleasant, but at the same time you realise he would happily kill you if the money was right.”

Reading People

Similar to gut instincts, the ability to read a person’s body language is incredibly beneficial to investigators. It can help them identify suspects and draw conclusions about their cases.

But it isn’t reliable.

Someone acting suspiciously does’t necessarily mean they’re guilty.

“They may be stressed or uncomfortable , or even drug effected,” says Neil. “Sometimes a very good liar won’t give themselves away with these things.”

“That’s why it’s imperative to read the whole body language but also look at all the other evidence. These are indicators, not answers. You use them to build your suspicions and explore some more.”

McNab agrees. “Some people are remarkably fantastic liars. One thing you do learn after being around for awhile — it’s almost never that someone will tell you the whole detailed, absolutely factual truth. They always hold something back. Sometimes because they don’t think you need to know, sometimes they’re concerned about the impact on other people.”

“Take your impressions away from an interview, by all means, it’s what you have to do. But then go and do your own investigation and substantiate it.”

Neil also stresses how important self awareness is when it comes to reading a person, as it can effect how much they divulge.

“If I fold my arms, if I’m not looking at the person, or if I look at my watch the person isn’t going to think I’m interested in them. It’s not just about reading somebody else, it’s about being mindful of your own body language.”


Methodology is paramount to any investigation. You need to trawl through absolutely everything and not become impatient for answers — that’s when you might miss something important.

“Never ever forget to make sure your basics are absolutely rock solid, and then you build your investigation, says McNab.

“The chronology has to be right and the mechanics of what happened has to be substantiated…Be really cold about it and establish your facts.”

He continues, “It’s a hard methodical slog. You don’t dismiss things until you have a good reason to. It’s almost like accounting procedure sometimes. You have to be very precise, you don’t ignore things, you don’t assume things. Every incident needs to be investigated, wrapped up, dismissed or proceeded with.”


Being objective and analytical is equally important in an investigation. You can have to approach it with an open mind and avoid getting tunnel vision.

“Be open to other people’s ideas. Be suspicious,” says Neil

“The need to remain objective is paramount to any investigation. Facts get you the result in court. Things need to proved in evidence. That’s the bottom line.”

Duncan elaborates on this point, highlighting the need to be self critical. You don’t just investigate the crime. You investigate your own approach to it.

“You have to be brutally objective of yourself,” he surmises. “Once you’ve got everything wrapped up and think it’s good, take a step back and an objective look to make sure you haven’t made the mistakes that other people do. It happens, we’re all human.

Communication Skills

Investigations require talking to people. A lot of them. If you aren’t adept at flexible communication, you aren’t going to get very far.

“You have to be able to talk to kings and crooks, all levels of people,” says Neil. “Information can come from unlikely sources, you have to be able to maintain confidences.”

Heightened levels of communication were particularly necessary during her time as a hostage negotiator and undercover.

“It’s more intense in a hostage situation because it’s all about communication. If you’re talking to someone face to face, you have to be so mindful of not only trying to read the person but also of your own body language…You’re trying to read the situation while also remaining neutral because people can pick that up, even on the phone.”

She also highlights listening skills as an imperative. “It’s not about your ability to talk. You have to be able to show empathy, compassion and patience. That’s all in addition to your other skills as an investigator.”

Street Smarts

Like with any profession, training is a necessity. But there’s a lot about the job that can’t be learned from study.

“The formal training you get in a classroom tells you the laws, and gives you the legal framework you have to operate in. And that’s nailed into you,” McNab explains.

“As a copper and investigation leads to an arrest which leads to a court case and you need to make sure that everything is bolted down.”

“That formal training is essential, but then you build on it with experience, good mentoring and sometimes even being thrown into a situation where you have to work it out yourself and get it right.”

You learn on your feet, that’s where a lot of it comes from. You learn from everything that happens. Good investigators need to have that hands on experience working with people.”

“Both are important,” says Neil. “The experience you gain on the job is very important. But you need to know how to gather evidence properly too.”

When it comes to skills that need to be developed with experience, Neil suggests the following. “Street smarts. They’re important. The ability to think quickly, I don’t think you’ll learn that in a classroom. I’m really big on communication, that is so important, and being able to read people. That’s where you’re able to start gaining trust.”

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