Unbelievable Tactics Police Actually Use

Here's why cops touch your taillight, plus more secret tactics police don't want you to know!


The cops play a big part in keeping our streets safe, and sometimes that means playing dirty. From slyly tracking your car to telling outright lies to your face, let’s investigate some of the shadiest, sneakiest, and downright most unbelievable tricks police officers actually use!

Taillight Touch

If you drive, you might’ve found yourself pulled over by the police before. Cops can do this for whatever reason they choose, but if they’re particularly suspicious of you, they’re likely to do something a bit weird, tap the taillight of your vehicle with their hand. But why?

Watch on YouTube

For a start, tapping the car might startle the driver and make them pause what they’re doing. So, if they’re trying to quickly hide away any illegal items, this short pause could be enough to catch them in the act.

That’s not all though! By exerting a little pressure on the taillight, the officer is also sneakily ensuring that the trunk is locked, so nobody can jump out from it and ambush them. Pretty clever, but that’s still not the sneakiest reason for doing it. That title is reserved for reason three: so they can leave their fingerprints on your car!

police tapping taillight

But why would a cop want to leave their own fingerprints on your taillight? It’s essentially a failsafe. Police can never be sure who they’re pulling over, and the person could turn out to be dangerous. So, by leaving prints on the car, if anything happens to the officer, that evidence can help people work out what happened.

These days though, security cameras are installed on almost every street corner anyway, and it’s standard practice for officers to have dash or body cams. So, the technique isn’t as useful as it once was. However, many cops still do it, and it’s taught in some police forces to this day.

Never Drink Cop Water

If you ever end up in the interrogation room, you should remember one simple thing: if the interrogator offers you a cup of water, don’t, under any circumstances, accept it. If that means being thirsty, you deal with it.

This is because the cops probably aren’t worrying about your hydration levels! This seemingly innocent gesture is actually a great way of stealing your DNA and fingerprints! By simply picking up a cup of water and taking a sip from it, you’ve left both your prints and saliva all over the cup. In other words, a veritable feast of data they can identify you with!

man drinking water

Typically, the police can’t collect a DNA sample from you unless they have a warrant. But if you leave your water cup behind after using it, it’s considered abandoned. Therefore, the police don’t need a warrant to take it and collect the sample.

And water isn’t the only thing you need to watch out for, either. The cops can legally collect your DNA from pretty much anything you use, a discarded tissue, an old cigarette butt, you name it!

You might be thinking “Why should I worry about this if I’ve done nothing wrong?” Well, it’s not common by any means, but corrupt coppers could take your DNA or fingerprints and use them to frame you for any manner of crime later down the line. So, by refusing water, you’re ensuring this can’t happen.

The Police Can Legally Lie To You

It’s definitely very illegal to lie to the police. In fact, it’s a great way to get yourself locked up if you’re caught! However, this rule doesn’t work both ways as the police are allowed to downright lie to your face if they think it will help them.

If a police officer suspects that you’ve committed a crime, but they don’t have any evidence, they might just lie and tell you your fingerprints have been found at the scene anyway. That way, if you’re innocent, you’ll still deny it, but if you’re guilty, they might trick you into confessing!

police stopping car

Cops have even been known to bluff about a supposed eyewitness that’s willing to testify against you! Of course, there is no eyewitness, but if they can make you believe there is, you might panic and admit to a crime.

One particularly notable case of cop deception dates back to the 1970s. Oregon state police suspected one Carl Mathiason of committing a burglary, so the investigating officer falsely told him that they’d found his fingerprints at the scene. Thinking he’d been caught, Mathiason confessed to the burglary.

Mathiason confession

Remarkably, even though Mathiason was convicted of the crime, the Supreme Court reversed the conviction on the grounds that the interrogation took place in a “coercive environment”! Mathiason was convicted in the end, but it shows that no matter how sneaky police are, it can still backfire sometimes.

The Lie Detection Myth

Lie detectors, or polygraph tests, are a common trope in detective movies. You know, those devices an interrogator straps onto a suspect before asking them a load of increasingly awkward questions. They’re supposed to tell when you’re lying and draw it all out in a neat little line graph.

The devices are real, but they’re not proven to detect lies, they just measure heartrate and breathing patterns, which change when you’re anxious. But even an honest person can get nervous when under interrogation, so the tests aren’t actually reliable.

polygraph test

Not everyone knows this though, which the police sneakily use to their advantage. Back in 2009, Californian Darious Antoine Mays was being questioned about his involvement in a particularly heinous crime. During questioning, the police strapped Darious up and gave him a polygraph test. Perhaps unsurprisingly, he denied all allegations.

However, the cops had rigged the test, so when it came back it looked like he’d completely failed. Because Darious thought he’d been caught out, when they showed him the results, he gave up and confessed to being at the crime scene! In reality, the test had proven nothing. So, even though polygraph tests don’t actually work, they are still useful.

Darious Antoine Mays confession


If you couldn’t already tell, the police are willing to go to some pretty great lengths in order to catch criminals. But none of those lengths are as ridiculous as the story below.

Malky McEwan, a now-retired policeman from Scotland, was on duty with his partner Dan when they received a report that someone had broken into the local rugby club. Malky and Dan rushed to the scene, but the door to the building was closed, and the two coppers had no idea where the burglars were.

They’d have to think fast. Luckily though, Dan had an idea! He turned to Malky and told him that on his signal, he needed to start barking like a dog. How on earth was that supposed to help?

police pretend to be dog

Before Malky could question it though, Dan had already marched right up to the door and shouted, “If you don’t come out now, I’ll send the dog in!”. Suddenly, Malky understood the plan.

Hardly believing what he was doing, he took a deep breath and started to bark loudly, doing his best impression of an angry Alsatian. Hopefully, the burglars would believe there was a real dog and show themselves out of fear. Lo and behold, they did show themselves! But not from fear.

It turned out, they’d actually been hiding on the roof of the building. That is, until the sight of a uniformed police officer pretending to be a dog caused them to burst out laughing. After that, the cops quickly spotted them and carried out the arrest. So, the trick didn’t quite work the way they intended, but it worked nonetheless!

police pretending to be dog

Good Cop Bad Cop

The ‘good cop, bad cop’ interrogation method is the oldest trick in the book because it works. A so-called ‘bad cop’ takes an aggressive, hostile stance towards a suspect, then a ‘good cop’ comes in and takes the opposite approach. It’s used by police forces all over the world and it’s so effective because of basic human psychology.

The ‘bad cop’ acts so overtly terrible that when the good cop comes in and acts nice, they seem way nicer than they would normally. The good cop can then exploit this and gain the trust of the suspect. Then, when it’s the bad cop’s turn to pick up the interrogation again, they act so threatening that it drives the suspect further into the good cop’s influence.

good cop bad cop

Cooperating with the good cop suddenly seems a lot better than having to deal with the bad cop, and so, suspects are more likely to give up information. Or, at least, they were. Because this technique is so well known, it’s lost some of its effectiveness.

The Meanings Behind Siren Sounds

Police sirens might seem like they’ve been solely designed to burst your eardrums, but their painfully high volume is essential for police to get around quickly and safely. Have you ever noticed there are actually a few different sirens sounds though? That’s not just random. Each one has its own specific use!

Most people don’t know, but there are three main sounds. First off, there’s “yelp mode”, which sounds like the clip below:

Watch on YouTube

That annoying sound is usually used when the police want to pull someone over. The short bursts of sound bounce off of walls better, making it easier to hear in built-up cities, where there are more people to pull over. Next up, there’s “wail mode”:

Watch on YouTube

Like the yelp, this siren alternates between high and low notes. However, it’s a lot slower, which means it’s best suited to emptier, rural environments where the drawn-out sound can reach further. Finally, we have the hi-low siren. This is your classic ‘nee-naw’ sound, it's more versatile than the others and you might hear it just about anywhere.

Watch on YouTube

Cryptic Codewords

If you’ve ever tried speaking pig Latin or writing letters in invisible ink, you’ll know how fun it can be to communicate in a secret language. But, of course, codes aren’t just for fun, US law enforcement actually use one to covertly talk to each other over their radios.

In fact, they use a lot. They’re called the ‘ten codes’. Each code starts with the number ‘ten’ to indicate something important is following, before a second number is spoken, which signals the specific phrase. For example, ‘10-4’ translates as ‘understood’, but ‘10-54’ means livestock on the highway. You wouldn’t want to get those two confused then!

police ten codes

When they were first established back in 1937, police codes had two primary uses. Firstly, they helped ensure communication was clear and easy to understand. Back then, radio technology wasn’t nearly as sophisticated as it is today, so radios were often disrupted by extreme static or other noise, making proper conversation difficult.

The codes also helped disguise police reports from the public. That way, operations could be kept a secret, and if a civilian accidentally tuned in, they’d just hear “10-98” rather than “jail break” and be saved the panic.

police 10 codes

These days, police codes are less popular. Because there’s no unified system, the same code sometimes means different things in each state. This can get confusing, so in 2006 the U.S federal government recommended police drop them entirely. Even so, many states still use the codes today.


One user on the question-and-answer website Quora described a conversation he’d had with a Californian cop. They’d been discussing a particular tactic the cop used to catch speeding cars. And, spoiler alert, it’s both sneaky and illegal.

In the alleged conversation, the cop explained that at night, he’d get a brown paper towel, wet it, and stick it to one of his headlights. Then, he’d cruise round until he noticed somebody speeding and tail them.

The paper towel makes it look like the cop’s headlight is malfunctioning, and people don’t expect cops to have faulty cars. So, the speeders would usually carry on, unaware of the cop directly behind them. Until of course, he turned his siren on, then they’d know they’re toast.

police shady tactic

And as soon as the copper pulled to a stop, the now-dry paper towel would fall off. So, if the speeder questioned the faulty light, the cop would simply act like he didn’t know what they were talking about. That’s shady.

Range-R Radar

The police have got some crazy new technology that lets them see through the walls of your house. They probably won’t be using it to see into your house, but it’s still a scary concept. The sly device is a high-tech radar called a Range-R, and law enforcement can use it to detect motion through walls, floors and ceilings!

police device range-r

By placing the Range-R on one of these surfaces and activating it, it emits radio waves, which travel through the surface and out into the space beyond. Then, when they hit something that’s in motion, they’re reflected back at the device and analyzed. Like this, it can detect movements as small as human breathing at up to 50 feet away!

Even crazier, advanced versions of the radar system can be installed on drones, flown over buildings, and used to generate three-dimensional maps of the interiors.

range-r drone

It is surprisingly legal but the FBI had been using it in secret for two whole years before it was finally revealed they had the technology in 2015. So, who knows what they’d been secretly mapping all that time!

Officials claim the radar was only being used in special rescue operations, and I’m sure it’s very useful for them. Even so, it gives me the heebie-jeebies to know one of these things could fly over my house and spy on me whenever the police fancy it, without me even knowing.

Bird Drones

Drones have been the subject of some controversy over the years. However, they can be equipped with all manner of shady surveillance devices and used for more nefarious reasons too.

In fact, the Pentagon has poured millions of dollars into developing a new, far sneakier way of spying on people. It’s called a nano hummingbird, and it’s a tiny, bird-shaped drone that’s so discreet that even if you saw it, you’d think nothing of it!

nano hummingbird drone pentagon

The little gizmo has a wingspan of just 6.5 inches and weighs less than an AA battery, despite packing a camera and microphone inside! So, an operator can make the drone fly and hover around, completely unbeknownst to the person under surveillance.

Before you start freaking out every time you see a bird, you can be reassured that despite its development being funded by the U.S. government, it hasn’t officially been rolled out in any police departments yet.

At least as far as we know. This is the Pentagon we’re talking about here, after all, and they can be pretty secretive. Intriguingly, though, U.S. police have reportedly expressed an interest in the tiny bird drones for surveillance purposes.

Watch on YouTube

What’s more, larger versions of incognito bird drones have already been rolled out by Spanish police forces and if they prove successful, we could expect to see a lot more of them flitting around our skies. Let’s hope this is one idea that doesn’t fly.

StarChase System

There’s no doubt that car chases make great movie scenes. But when the cops are trying to catch criminals in real-life, high-speed chases pose a serious risk to both police officers and civilians. The solution? StarChase, of course!


This nifty little contraption might not look like much, but it has an in-built GPS tracker and can be fired at a fleeing vehicle from a launcher hidden behind the grille of a police car. While mid-chase, police can use a laser pointer to target the suspect’s vehicle.

Once in position, hitting a button releases a build-up of compressed air, sending the dart flying forwards. Then, when it hits its target, a layer of industrial strength glue makes sure it’s not going anywhere.

Watch on YouTube

And the sneakiest thing about it is that the device is only about the size of a golf ball, making it near enough unnoticeable unless you’re looking for it. After the StarChase is secured on the vehicle, police can slow down, drop back, and track it with their GPS, avoiding a lengthy and dangerous car chase. And they also get to feel like a budget version of Batman.


Batman isn’t the only Superhero movie that police have apparently taken inspiration from. Another super-sneaky invention in their arsenal is the Bola-wrap, a device that is more in the realms of Spiderman than the Caped Crusader.

The handheld device has a built-in laser to help the officer aim and shoots a powerful Kevlar tether at a suspect’s arms or legs at a blindingly fast 513 feet a second. Once it hits somebody, the Kevlar snaps right around them, restraining them without any force necessary!

Watch on YouTube

And there’s no getting out of this bad boy, either, once it’s got you, it’s got you tight. Which makes it the perfect tool to snare a fleeing suspect! Despite being used in over 600 law enforcement agencies across the US, it’s still relatively new technology.

The Sting Operation

Cops aren’t the only ones that can be sneaky, criminals can be even sneakier! So sometimes, the police have to get real inventive to catch them, such as the sting operation. Typically, stings involve a cop going undercover and deceiving a suspect, often by posing as a partner in crime.

That way, they can gain the suspect’s trust and gather evidence right under their noses. And when enough evidence has been collected to put the criminal behind bars, away they go!

In a particularly wild sting from back in 2012, a young police officer called Alex Salinas posed as a student in a Californian high school. Police knew a group of pupils were selling illegal contraband in the school, and it was Alex’s job to find out who.

the sting operation alex salinas

So, he joined the school under a fake name and acted like any other student, attending class, watching football games, and even completing homework assignments! But little did his classmates know, he was actually spying on them the whole time.

If you’ve ever seen 21 Jump Street, you might find that premise familiar! Eight months after joining the school, Alex had got enough evidence to arrest 14 people in total, and the mission was a roaring success.

alex salinas mission

Phoney Phrasing

If I was told to do something by a police officer, you can be damn sure I’d do it; I’d rather avoid jail! But it turns out, sometimes you don’t need to comply with their demands. The police use language very carefully to trick you into doing what they say, even if you don’t have to!

Let’s say you’re driving down the road when a copper pulls you over and barks, “I’m going to need you to let me search your vehicle.” That sounds like an order, right? Well, it’s actually not. Sure, the officer is saying he “needs” to conduct a search, but he's not legally ordering it; it just sounds like he is because of the way he’s phrased it.

police asking a car driver

Because police officers are authority figures, we tend to feel compelled to do as they say. But a lot of the time, you’re actually well within your rights to refuse them! So, if a police officer ever says “Ma’am, I’m going to need you to do the worm”, you’ll be relieved to know that you can decline the request!

Playing Dumb

Everyone is unique and special in their own way, or at least, that’s what our mothers tells us. But undeniably, some people are a little less “switched on” than others. And the police know this all too well. So, sometimes, they’ll employ a tricksy little interrogation tactic where they pretend to be less intelligent than they actually are. But what could that possibly achieve?

police interrogation

If a suspect thinks the officer questioning them is shrewd, professional, and on the ball, they’ll have their guard up the whole time. But let’s say the interrogator seems a little on the slow side, well, in that case, the suspect is far more likely to let their guard down and be more careless than they otherwise would have. And they might let slip an important piece of information!

According to retired New Jersey cop David Ambrose, this trick works even better on affluent, successful people who are quick to turn their noses up at someone they see as inferior.

icon Top Picks For You

Top Picks For You

Secret Reasons You Don't Know About Everyday Things
Symbols You Don't Know the Meaning & Origins of
The SCP Foundation Explained
Paranormal Games You Should Never Ever Risk Playing
icon Popular


icon More From Fun Facts

More From Fun Facts

icon More From Secrets

More From Secrets