Probable Cause


Your observations of the suspect’s suspicious behavior led you to reasonably believe the suspect was armed and about to commit a crime - less than probable cause

Detective Lieutenant Barry M. Baker (ret.) is a 32 year veteran of the Baltimore Police Department.

Probable cause is a compilation of facts, based on evidence, to indicate that a person probably committed the crime or offense being alleged. Probable cause to  arrest requires less evidence than is required to convict a person beyond a reasonable doubt. Many police officers take the low road, and they choose brevity over detail in their written statements of probable cause.

You’ll hear police officers whine about criminals being released, before officers are done with their paperwork. That’s an exaggeration, but the rapid release of those charged criminally is often the result of an officer’s failure to provide the reviewing court official all of the information available.

Probable Cause Scenario

In the scenario, you’re a patrol officer in Baltimore. The area you patrol is mostly residential consisting of row house dwellings and densely populated. This community has a high rate of violent crime to include robberies, shootings and homicides. You’re sitting in your patrol car on a parking area a block from the intersection of two main thoroughfares. On the northwest corner of that intersection sets a storefront liquor store. 

The month is August, and the time is midday. Weather is clear and sunny with a temperature of about 90 degrees Fahrenheit. Most men on the street are dressed in shorts; tee shirts, or no shirts.

The liquor store is experiencing a high rate of customer traffic. One man standing in front of the store is conspicuous by his dress and manner. He’s wearing a dark color baseball cap; dark glasses; brown hoody with the hood over his head and tied tightly beneath his chin; blue jeans and tennis shoes. 

For fifteen minutes, you observe customers enter and exit the store. Your suspect periodically looks into the store through the front door, before he steps back and looks in all directions. He repeats this movement at least ten times during your observation.

More Suspicious Actions – Still Less than Probable Cause

You notice the suspect repeatedly putting his right hand over the right pocket of his hoody. The pocket appears to hang a bit low indicating the pocket contains an item of some weight.

An elderly woman exits the liquor store carrying two plastic bags with items from the store. The suspect puts his right hand in the pocket of his hoody, and he begins following the woman. She walks east and then north at the intersection with the suspect following directly behind her. You’re now concerned the woman may be victimized by the suspect.

The woman approaches the alley entrance behind the liquor store as two young men riding bicycles emerge from the alley. They stop directly in front of the woman, and it is evident that the woman knows both men. She hands her bags to one man who hang the bags on the handle bar of his bicycle. He rides back into the alley, and the second man walks with the woman into the alley.

When the woman met the young men, your suspect turned and walked back to the front of the liquor store. You decide to conduct a stop and frisk, because you reasonably believe the suspect is armed with a dangerous weapon.

U.S. Supreme Court - Terry v. Ohio, 392 U.S. 1 (1968) Primary Holding

“Under the Fourth Amendment of the U.S. Constitution, a police officer may stop a suspect on the street and frisk him or her without probable cause to arrest, if the police officer has a reasonable suspicion that the person has committed, is committing, or is about to commit a crime and has a reasonable belief that the person may be armed and presently dangerous.”

You drive your patrol car onto the northbound thoroughfare, and you reach the intersection as the traffic light turns red. The suspect is looking directly in your direction. You activate your turn signal to see if turning toward the suspect will illicit any reaction from him. It does. The suspect walks eastbound to the corner, and he turns northbound without taking his eyes off you. Once he reaches the alley entrance, he’ll run and discard his gun if he has a gun.

You Take Action on Reasonable Suspicion – Less than Probable Cause

You check the traffic in both directions, and you accelerate northbound through the red light. The suspect simultaneously begins running toward the alley entrance. Just as you predicted, the suspect turns into the alley. Your timing is  perfect, and you see him toss a small handgun into the backyard of a dwelling. The suspect continues running; until, he reaches the end of the alley where he stops, drops to his knees, and raises his hands above his head.

The suspect offers no resistance, and he follows all of your commands. You conduct a search of the suspect incident to the arrest. He is not in possession of a wallet or any items of personal identification. This suspect is smarter than most, because he knows the value of remaining silent. He won’t even give you his name. You place him into your car, and you drive backward in the alley. You stop in front of the yard where he threw the gun. He realizes you saw him toss the gun, and he makes his first relevant statement, “It’s not a real gun.”

It’s a Walther PPK, or is it?

You walk into the yard, and you spot the gun on the ground next to an open metal trash can. You recognize the gun as a Walther PPK; a gun made famous by the James Bond movies. So much for the suspect’s statement, or is it? When you try to clear the weapon, you realize it is not a real gun. It’s not a toy, but it’s a manufactured replica of the real thing. Some parts are operable for realism; however, the replica is not capable of loading or firing any kind of projectile.

Evidence for Probable Cause

Let’s examine the evidence as it relates to the establishment of probable cause for you to make an arrest:

Your observations of the suspect’s suspicious behavior led you to reasonably believe the suspect was armed and about to commit a crime – less than probable cause.

The suspect runs when you approach. His attempt to elude you is more evidence of guilt, but it is still less than probable cause.

The suspect discards what you can clearly identify as a handgun. You have now established probable cause to arrest the suspect for possession of a handgun.

You arrest the suspect based on probable cause, but the handgun does not meet the legal definition of a handgun.

There is no criminal violation for possession of a replica handgun. Your probable cause relating to the possession of a handgun has evaporated. You must release the suspect from custody if the suspect committed no other violation of law. 

The fact the suspect would not provide you with identifying information or answers to other questions is not unlawful. His refusal to answer your questions is his Constitutional right against self-incrimination. Only one question needs to be answered at this point. Did the suspect commit a crime in your presence during this scenario that would subject him to arrest?

Of course, he did.


Subtitle 1 – Crimes Against Public Health and Safety Section 10-110 – Litter Control Law.

2) (i) A person who disposes of litter in violation of this section in an amount not exceeding 100 pounds or 27 cubic feet and not for commercial gain is guilty of a misdemeanor and on conviction is subject to imprisonment not exceeding 30 days or a fine not exceeding $1,500 or both.

Some people would argue that arresting your suspect for littering wouldn’t be fair. Well, everybody is entitled to his or her opinion. In fact, the charge would be legitimate, and it would serve your purpose to positively identify the suspect. There is a reasonable probability that your continuing investigation could implicate your suspect in a previous robbery or robberies.

Another Possibility

Let’s throw another possibility into this scenario. What if the gun had been removed from the yard by an unknown person while you were arresting the suspect? You’d still have probable cause to arrest based solely on your observation of the suspect discarding the gun. This situation would severely weaken prosecution, but it would not alter your probable cause. The irony is that your recovery of the replica saved the suspect from being charged with possessing a real gun.

Let’s throw another what if into the equation. Recall that you found the gun lying on the ground next to an open metal trash container. What if the gun had gone into the trash can when thrown away by the suspect? As long as the trash can was being used for refuse and not some other purpose such as storage, disposal of the replica into the trash container would comply with the littering statute.  Therefore, the suspect would not be guilty of littering.

Everything is Complicated in the Beginning

In the beginning of your police career, everything is going to be complicated, because it’s new to you. Just like many things, probable cause is a process.  Sometimes, probable cause will present itself in obvious form. As in this scenario, if you had observed the suspect rob the elderly woman victim at gunpoint, your probable cause would have been immediate, overwhelming and actionable. Or, as in this scenario, you may have to be patient and build toward probable cause.

Related Content for Probable Cause



Becoming a Police Officer

An Insider's Guide to a Career in Law Enforcement by Barry M. Baker

Choosing A Police Department
Police Hiring Process
Police Academy
Police Report Writing

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