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Drop the Pen! What Every Writer Should Know About Real Police Work: Traffic Stops, Part Two

In this follow-up to last month’s article, former detective David Lane Williams takes writers deeper into the world of real police work. From the nuances of reasonable suspicion to the tactics of safe vehicle approaches, Williams explains the legal, procedural, and tactical realities behind every traffic stop—helping crime and mystery writers bring authenticity and accuracy to their fiction.

By David Lane Williams


Last month, we discussed traffic stops, focusing primarily on how police officers stopping vehicles based on relatively minor offenses can lead to the detection and arrest of violent criminals. Even if you’re writing a detective procedural, it’s important that you understand the constitutional and tactical considerations of a legal and safe stop in the grand scheme of policing. This month, I want to continue with the traffic stop concept, expanding on best practices. Traffic stops are performed thousands of times each day, and writers of crime fiction and true crime need to have a solid understanding of how they are performed to show they’ve done the research and know this subject better than the average Joe Citizen. There is a procedure taught at most academies nowadays, and I think it is enlightening to understand the way these things should be done. Let’s take it step by step. 

Determine Reasonable Suspicion or Probable Cause

Let’s say your fictional officer needs to stop a car because the driver matches the description of a bank robber from the previous shift. Your officer needs to make the stop in a legal and safe manner. The first thing he must decide (and be ready to defend) is the legal reason for the stop. Officers in the U.S. can’t just go around stopping every car they pass. We’ve all seen the awful ramifications of such an approach. There are basically two ways to make a legal, constitutionally sound traffic stop: Reasonable Suspicion or Probable Cause. 

Reasonable suspicion that a driver or occupant of a moving vehicle has committed a crime or is about to commit one is an acceptable reason for stopping a vehicle. It is, however, the least resilient tactic to the scrutiny of a defense attorney, judge, and/or jury. The officer must be able to swear under oath that, based on his training and experience, he suspected the occupants of a vehicle of doing or about to do a crime. Reasonable suspicion stops are done with less frequency than even a decade ago, because of the inevitable attack it will receive from the person’s attorney if the case ever goes to trial. Most officers will wait until they notice an infraction, such as making a turn without a signal or weaving in and out of lanes. Delaying a stop for actual probable cause—AKA evidence— instead of relying solely on suspicion, puts the officer in a better position to defend his actions if the case goes to trial.

Thus, you may opt to have your fictional officer stop a car based on a “gut feeling,” but you’ve placed him in a legally precarious situation that most veteran officers wouldn’t actually choose. It can still work, but your character is in a better position if he is patient and waits to spot an actual infraction about which he can testify under oath. (Go back and read the previous month’s article if you need more detail on the difference between a Reasonable Suspicion stop and one based on Probable Cause.)

Prepare for the Stop

Preparing for the stop means calling the license plate, description, and location to the Dispatch Center so other officers will know where you are and what kind of vehicle they should look for if the officer making the stop gets attacked. The Hollywood version of a cop stopping a car in a dark alley and not letting anyone know is macho hooey and should never happen in real life (or your fiction unless you want to show a police character performing at a level of incompetence or recklessness).

Parking the Patrol Vehicle

Safe parking of the patrol vehicle calls for turning on the emergency lights and pulling in behind the stopped vehicle. At night, a patrol officer will also use a car-mounted beacon-style light in such a way that it reflects in the side mirror of the stopped car. This adds an additional layer of protection because the other driver has limited visibility due to the glare. Officers know the glare is irritating, but it is designed to give them an edge if the occupants are intent on doing them harm.

The officer will then park the squad car at a slight angle with the engine block canted to the left. This has two advantages. First, the officer can cover behind the engine block if the occupants of the other vehicle come out shooting. Second, the parked squad car will careen to the left instead of straight into the officer if another car hits it from behind. 

Approaching the Vehicle

Approaching the vehicle can be done by either stepping up to the driver’s door or around the back of the stopped vehicle just behind the passenger door. I preferred the second method when I worked at night. Most people will be watching for the officer to approach from their left. Coming up on the right side of their car allowed me to be beside the vehicle and use my flashlight to see if the occupants were holding a weapon before they even knew I was close. 

Either way, officers will touch the trunk compartment door as they pass the rear fender. This action marks the suspect vehicle with the officer’s fingerprints and DNA. Should the suspect “rabbit” (flee), his car will carry definitive evidence of the encounter. It also lets the officer make sure the trunk is fully closed in case there is anyone in the trunk intent on doing him harm. 

Once the officer is near the car, he should identify himself and his agency right away. This has a proven effect of calming concerns from the driver that the officer might be corrupt. Corrupt cops don’t tend to give their names, and this small detail can make all the difference in terms of keeping the tone polite and professional. 

I am also a big believer that officers should clearly state why they pulled the car over, e.g., “I pulled you over because you were speeding through a school zone.” Again, this has a dampening effect on any driver revving up to argue. The officer should be clear, forthright, and professional, which is what it will sound like to jurors listening to the officer’s body camera recording if this thing ever goes to trial. 

Positioning At the Vehicle

I roll my eyes at cop shows where the police officer is talking straight down into the window of the suspect vehicle. The problem with standing right beside the driver’s window is that this position puts you in the line of fire should he turn homicidal. Bullets go through car doors like toothpicks through those little Christmas party sausages. Don’t let your fictional officer stand right by the door. I’ll surmise he was poorly trained or that he is about to get shot in the groin.

Instead, officers are taught to stand adjacent to the thick metal door frame behind the driver’s seat. This space has the tactical advantage of keeping the driver in sight while also making it more difficult for him to accurately fire a weapon backward and over his left shoulder. Try it next time you’re in the driver’s seat. Point your finger like you’re a kid playing with a pretend space phaser and see if you can “photon blast” someone standing back there. You can, but it’s slow and clumsy—the advantage in a split-second attack goes to the officer.

Remember: Officer survival is part tactics and part practice, but all mindset. A well-trained police officer will be thinking about these concepts as he approaches the car. 

Background Check

By now, your officer has collected pertinent paperwork, including the vehicle registration (not all states require this), proof of insurance, and the driver’s license. The officer has conversed with the occupants, determined what, if any, violations have occurred, and retreated toward his own car to increase the safety distance. Now the officer will either type in the occupants’ identification into a mobile computer or call it out to the Dispatch Center. 

I preferred to keep my eyes on the car by calling Dispatch on the radio. Oftentimes, I would do this while standing behind the trunk of my own car, again so that I would have the protection of my vehicle should occupants in the stopped car come out firing. The last place I would want to be in that event would be sitting comfy—and trapped—in my driver’s seat.

Once the cop has determined there are no outstanding arrest warrants for the people in the car, he’ll decide whether to issue a warning or a citation. Once this is done, the officer needs to make a formal announcement along the lines of, “You’re free to go.” 

This is where things might get tricky. Once the person who was detained has been informed he is free to go, he is…free to go. But, this is also when the officer may ask if there is anything illegal in the car. If the driver says, “No,” but he does it in a less-than-credible manner, the officer might follow up with, “So, you wouldn’t mind if I did a quick search, then?” 

Why then? Why not ask to search before the officer has lifted the detention? Here’s the thing: any search of a vehicle (or anywhere considered private from the prying eyes of government) done while a person is in custody is likely to get thrown out of court. In simplest terms, a person in custody may not feel they have a choice but to let that government agent search their car. Thus, any search during the stop could, and probably should, be considered involuntary. You can’t volunteer to allow a search if you don’t believe you have an option. The case is likely to be dismissed, even if you were to find a severed head and a bloody axe in the trunk. 

Officers who are looking to make lots of drug-related arrests use this tactic often. Mentioning to the driver that he is free to leave, but following up with a request to search the car is a workaround, and defense attorneys everywhere just groaned. I can’t say I blame them. This strategy pushes the limits of the Fourth Amendment, and I’m not an advocate for using it during most traffic stops. That said, this is a standard drug interdiction technique, and you may decide to use it to propel your storyline forward. 

Bloody axe, anyone?

A Word on “Do you know who I am?” 

I don’t care if you’re a minister taking her family out for a picnic after church, Senator So & So’s aide, or a rookie attorney who just passed the bar; cops don’t know “who you are,” and they don’t particularly care. They know they’ve stopped you for a reason, and they expect to speak with you and investigate further. 

You wanna make a cop mock you long after the traffic stop? Say, “Do you know who I am?” when he approaches the car. You’ll be the belle of the squad room when he tells his buddies about it later. 

That’s it for this month. Until then, be safe…just not too safe. You’ve got a job to do, after all. Onward.

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David Lane Williams Shane McKnight David Lane Williams Shane McKnight

Drop the Pen! What Every Writer Should Know About Real Police Work: Legal Justification for a Traffic Stop

Former police officer and author David Lane Williams explains how traffic stops really work, what makes them constitutionally sound, and why understanding “probable cause” is essential for writers crafting authentic crime, mystery, or thriller scenes.


Patrol officers have many different roles day-to-day. They may bust out of the station for a domestic violence call or be dispatched to an armed robbery while eating lunch. The next hour may be taken up with a traffic accident, followed by a shoplifting complaint. An elderly woman may call about hearing sounds beneath her house, relieved when the smudged and dusty officer reappears from the crawl space to report the intruder was only a raccoon. In other words, the mission of protect and serve stays the same, though the tasks involved change by the minute. 

The most visible duty, though, has to do with traffic stops. We’ve all seen them, and many of us have been the subject of a stop. Perhaps we were speeding, didn’t use a turn signal, weaving in and out of lanes or tailgating another driver. There are any number of reasons a patrol officer might pull us over, but this aspect of police work is one of the least understood. 

Even if you write exclusively about detective work, it is important that you understand the reasons for and mechanics of traffic stops. I can’t tell you how many times as a detective that I asked patrol officers to pull over a car for me so I could locate a suspect, find contraband specific to the case I was working, or to make an arrest for a violent crime. Stopping vehicles using the trappings of a patrol vehicle such as the emergency lights, decals and insignia, and public address systems is the safest way. 

Your protagonist investigator may need to stop a fictional “bad guy” while he’s driving a car in which he has hidden an axe he used in the murder of his business partner. Perhaps your detective has gotten information the suspect will be moving the axe from his basement in order to throw it in a lake. Your investigator needs to stop the guy quickly to secure the evidence, and the safest way is to call in help from Patrol. 

There are a lot of factors that go into the decision to stop a car. It must be done in the safest way, which means controlling the tactical advantage at all times. It must also be done in a constitutionally sound manner, both because it is wrong to violate someone’s civil rights, and also because not doing so is the fastest way to get your case thrown out in court. 

There is no such thing as a “routine” traffic stop. Every stop carries the possibility of ending badly. People don’t much like being pulled over by police, even if they know they’ve been speeding, driving drunk, or throwing litter out of their pickup truck. Some people, however, hate it so much that they’re willing to murder the officer who stopped them. 

There are people in this world with felony warrants out for their arrest. Some are looking at life behind bars once they’re caught, so the safety of the officer and anyone else unlucky to be in the line of fire are of no concern. They will die in prison if they don’t get away from the cop who stopped them, and violence is a choice too many are willing to make. 

Thus, every officer coming out of a police academy in America is trained on how to safely and professionally conduct such a stop. Unfortunately, not everyone does it the way they were trained, but the preparatory foundation is a starting point for this discussion. Let’s explore the most professional, least confrontational way of conducting a temporary detention of a driver for an infraction. 

In a traffic stop several things should happen as a matter of constitutional law, training, experience, and a totality of the circumstances. First and foremost is the stop itself. It is only legal for police officers to stop you while driving a car if they have evidence—probable cause—that you have committed a crime or an infraction, or they have a reasonable suspicion that you are about to commit a crime or just committed one. 

Examples of reasonable suspicion that have come before the Supreme Court include stopping cars coming out of a parking lot where there is known drug trafficking (this is constitutionally limited and not used as often anymore), “furtive” movements such as a guy ducking into the shadows when a patrol car cruises by, or someone sprinting away when a police officer approaches. All suspicious, but such subjective decisions on the part of the officer based on his or her training and experience are ripe for misinterpretation, abuse, and second-guessing. 

Probable cause, however, is less subjective, which is why most officers wait to make a stop until they have actual evidence and not just a suspicion of misdeed. This is a critical concept for writers of mystery and thriller fiction to understand. Yes, officers could stop a car based on suspicious circumstances, but veteran cops soon learn that they will spend less time in court being grilled on the stand by a defense attorney if they spot evidence of an actual infraction before turning on their emergency lights. 

This is why some of you may have felt like a police car was following you for too long. You start muttering profanities and staring into your rearview mirror. I’m sure this is where the phrase, “Doesn’t he have better things to do with his time?” came from. Perhaps. It could be that the officer is simply driving in the same direction as you, but it could also be that he is waiting until he has verifiable probable cause. This is especially true if he is trying to record said evidence on his dash camera. 

For example, he may see a person speeding down the road, crossing over the median stripes, or their car has a burned-out taillight. Any of those would constitute probable cause for a stop. 

I can almost hear some of you groaning right now. Stopping someone for a defective taillight? Are you kidding me? Stopping a car for speeding or suspicion of drunk driving is one thing, but why would an officer “waste” time pulling over a car for a light bulb issue? 

There are two answers to this. First, every state has laws regulating safety features on a car, and working lights are part of that package. 

I grant you a broken taillight isn’t on the same level of offense as a driver speeding through a school zone or drunkenly weaving back and forth in traffic. That said, every officer I know has stopped someone for a lower-end priority infraction such as a defective light, expired license tags, or a busted muffler only to find out the driver is a wanted felon. 

In 1995 Oklahoma State Trooper Charlie Hanger pulled over a yellow Mercury for the minor infraction of missing a license plate. To his surprise, Trooper Hanger came to discover the driver of the Mercury was one Timothy McVeigh who had just perpetrated the largest domestic terrorism attack in the history of this nation. McVeigh had worked with other white supremacist/government separatists to blow up the Alfred P. Murrah building in downtown Oklahoma City. 

That one stop helped the FBI retrieve an avalanche of evidence later used against McVeigh at trial. Would McVeigh have gotten away with the murder of one-hundred-sixty-eight and the injury of another six-hundred-eighty people had Trooper Hanger not stopped him for a minor infraction? Potentially, yes, but I think it is also fair to wonder how many others Trooper Hanger saved by stopping McVeigh such a short time after his cowardly act. It was courageous, savvy police work, and it illustrates the potential value in such traffic stops. 

Next month I’ll walk you through how a safe, constitutionally sound, and effective traffic stop should go. Until then, be safe…just not too safe. Onward.

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