What Does It Take to Establish Probable Cause?

search2a.jpgIn a concurring opinion in United States v. McClain, No. 04-5887 (6th Cir., Dec. 2, 2005), Chief Judge Danny Boggs of the U.S. Court of Appeals for the Sixth Circuit seeks to explain what “probable cause” entails. Under the Fourth Amendment, law enforcement officials often must have probable cause to believe that the place to be searched contains evidence of a crime in order to conduct a search. In describing the standard, however, Judge Boggs defines it as a ridiculously low threshold:

Finally, a word on “probable cause.” While courts have resisted mightily putting a number on probable cause, see Maryland v. Pringle, 540 U.S. 366, 371 (2003), at bottom a review of cases indicates that there must be some, albeit inchoate, feeling as to what kind of probability constitutes probable cause. My reading is that it does not require a belief that there is more than a 50% probability of evidence being found in a particular location. See, e.g., United States v. Gourde, 382 F.3d 1003, 1015 (9th Cir. 2004) (Gould, J., concurring) (collecting cases). If that were the case, one could never get a search warrant to search all three cars of a person for whom there was overwhelming evidence of general drug dealing, and specific evidence of a drug transaction the proceeds of which were now certainly in one of three cars in his garage, and certainly not in any of the others. However, to be more than a hunch or a supposition, in my own mind, requires a legitimate belief that there is more than a 5 or 10 percent chance that a crime is being committed or that evidence is in a particular location. Using this standard, my judgment would be that there was probable cause to believe that criminal activity was afoot in the house, based on the information on which the officers could reasonably rely that there was not a legitimate reason for activity in the house.

This strikes me as far too low a precentage. Just five to ten percent? It would be nearly impossible for law enforcement officials to fail to establish probable cause, unless they were just conducting a random search. If probable cause is just slightly more than five to ten percent, then what number would Judge Boggs give for “reasonable suspicion,” the lower standard for the police to engage in a stop? One percent?

Hat Tip: How Appealing

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10 Responses

  1. John Armstrong says:

    What srikes me as most odd is how for once a seeming innumeracy leads to more willingness to turn to numbers. Yes, the case he described leads to an actual probability (although I think he mismodeled the situation), but in general the real world is simply too nuanced to assign a number to a given situation. Do we try to assign a number to “reasonable doubt”, for instance?

  2. Orin S. Kerr says:

    Judge Boggs is just wrong, I think. I plan to blog about it shortly.

  3. Mike says:

    So much for originalism or textualism. “Probable” equals 5 – 10%? Yet another example of conservative judicial activism. (By the way, when are conservatives going to “cowboy[girl] up” and admit the judges on “their” side are just as activist as many of the judges on the Ninth Circuit?)

  4. Judge Boggs and Probable Cause:

    A number of law bloggers have pointed out the paragraph in a

  5. If, By “Probable,” You Mean a 5% Chance…

    probable: likely but not certain to be or become true or real; “a likely result”; “he foresaw a probable loss”

    The Chief Judge of the Sixth Circuit Court of A…

  6. Kevin Mcclain says:

    Judge Boggs is smarter than given credit for. While everyone is so interested in the off the wall coments that pertain to low percentages and fleets of cars to acheive those ideas. Everyone is missing the fact that this is the first time that good faith has been applied to a residence. Not to mention after a warrantless entry! I need help getting the word out about this case regardless of what you might think of me. I’m the defendant.

  7. K. Erdahl says:

    How can probable cause be found on only one sided investigations? Doesn’t a full investigation have to involve checking into the parties involved with an accusation? You can’t possibly find that probable cause exists if you only have one part of a story. To me when an accusation occurs, there should be time to talk to everyone who is named in that accusation, before one jumps to the conclusion that something did occur. As in the case of an accusation of child sexual molestation. Not all children tell the truth. Some of them, especially the older ones, make accusations to get back at someone, because they are angry. Some children from broken homes make accusations, because they don’t want rules that they have been told they will have if they live with one parent over the other. Ie. no running around after a certain time at night, no make-up, etc… Not all people do what they are accused of. There needs to be a complete investigation to decide that something did happen. And the Ramey warrant needs tighter constraints put on it. A police officer should have to really proove that there is a dire need to get one. When there has only been an interview with the victim and nothing else done, there is no probable cause to arrest. There is probable cause to investigate, but not to arrest.


    Probable Cause is often over looked by law enforcement, and the courts accept fabricated statements when Probable Cause is of issue. In order for a person to be arrested or even cited, Probable Cuse must be met. Most Police Officer learn Probable Cause at the Police Academy, for some reason they don’t use the requirements.

  9. 2cents says:

    Many officers use probable cause as a substition for completing a full investigation. After a crime has been commited, do not make yourself available to law enforcement, even if you feel you were the victim! If the cops cannot find you, they cannot arrest you if they happen to believe the other person’s story. The threshold for p/c is very low. If the cops cannot find you, it forces them seek an arrest warrant from a judge or to submit the paperwork to the state attorney, both of which have much more common sense than cops do! Avoid police contact at all costs, take it from me. I have 4 permanent felonies on my arrest record now, the cops figured out the truth the next day and the state attorney declined to prosecute. So i could have emerged from the situation unscathed had i avoided police contact!!! Even if you do something “in self defense” do not talk to the cops! Call your lawyer right away, let him talk to the cops on your behalf, get outta there, get a hotel room, just get away!

  10. 2cents says:

    Another note: I don’t condone running from police, but if the police haven’t arrived yet, then you are not running from them! The one exception would be leaving the scene of an accident which IS a crime, and i do not condone that.