That’s right. Probable cause is the proverbial gas that fuels the warrant engine, it is the electricity that drives the warrant train down the track, and it is the wind beneath a warrant’s wings. All bad metaphors aside, you probably get the point by now. The police are only allowed to get a warrant if they show the judge that probable cause exists.
1. More Than a Hunch and Less Than Clear Proof
Volumes and volumes have been (and will continue to be) written, in books, in law articles, and in judicial opinions about the concept of “probable cause.” That is because it is just vague enough, just elusive enough, not to be pinned down by any perfect definition.
In fact, the U.S. Constitution is a remarkable document in that regard. The drafters of the Constitution were very careful, with an almost supernatural power, to craft terms and standards that projected a general sense of what was needed, while still giving the standard enough flexibility to remain relevant two centuries later. Such is the “probable cause” standard.
One relatively solid definition of probable cause is called the “fair probability test.” That test states that probable cause to search exists if there is “a fair probability that contraband or evidence of crime will be found in a particular place.”
In other words, if there is good chance that evidence of illegality will be found somewhere specific, then a judge will sign a warrant for that place to be searched. Will a policeman’s hunch be enough? Absolutely not. The police, in the warrant application itself, must point to objective facts (those facts that others could observe and evaluate) to support a claim of probable cause. A hunch, or a gut instinct, will not suffice because that is purely subjective.
By the same token, does the police officer have to have 100% proof that the drugs will be found in the suspect’s closet? No. Crystal clear proof is too high a burden. Probable cause simply calls for there to be a good chance, or fair probability, based on measurable facts that evidence of a crime will be discovered in the place sought to be searched.
2. What Does Probable Cause Look Like in a Warrant Application?
An affidavit, signed by a police officer, asking for a search warrant in a drug case (or any case for that matter) is almost entirely a description of the probable cause in that case. The police, often with the help of prosecutors, will take great pains to write a lengthy 20- to 70-page document that is full of facts and observations to show that enough probable cause exists for a warrant to be issued.
In that vein, probable cause to support a warrant is normally based on:
1.The personal observations of police officers;
2.Hearsay from reliable sources; or
3.Anonymous tips that can be supported by other evidence.
We will focus on the first source – personal observations by police officers – because that constitutes the largest portion of what makes up the probable cause in any warrant.
To begin, recall that the Fourth Amendment calls for a warrant to be based on “Oath or affirmation.” That requirement means that the person writing the warrant application must swear that the information in the warrant is true – under penalty of perjury. That requirement essentially is calling for a particular level of truthfulness surrounding the warrant application.
In other words, it is not enough for there to be factual information to support a finding of probable cause. Indeed, there must also be a sense that the source of the information, usually a police officer, is reliable. In virtually all cases, the personal knowledge of a police officer, or the knowledge of a fellow officer, is presumed to be reliable.
Now, police officer observations in a warrant can take several forms, as follows:
- Observation of an Isolated Incident. Sometimes one event could provide the requisite probable cause for a search. For example, probable cause existed in a case in which police officers observed a suspect and his friends:
- Speaking on cell phones,
- Looking into the back seat of a car where the cops already believed that drugs were stashed in secret compartment,
- Checking for police, and
- Moving in and out of cars in a manner that the cops believed was consistent with a drug transaction.
- Sophisticated Surveillance by a Team of Investigators. Opposite of the single incident is the narrative in a warrant application of a lengthy investigation to support the execution of a warrant. For example, probable cause for a warrant to search a home included observations of the suspect, with a drug record:
- Driving away in a car used to transfer cocaine into a trailer truck, with the driver of the truck stating that the “load car” would return,
- Acting suspiciously, and
- Driving the “load car” near his home.
Taking all of the above together, you can see that probable cause is the touchstone that allows law enforcement to search and seize with a warrant. That means that if you are ever in a situation in which the police tell you they are executing a search warrant, make sure that you see the warrant and otherwise allow the police to follow through with executing the warrant.
If they discover something that implicates you, then the first thing you will do once you get to court – with the help of your attorney, of course – is challenge whether the police actually had probable cause to get that warrant in the first place. As the title to this section tells you: No probable cause? Then no warrant. Moreover, if the warrant was invalid, then anything that the cops seized as evidence will be inadmissible at trial.