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by Peter Moskos

August 12, 2016

How do you define "reasonable suspicion" and "probable cause"?

It's not easy. Trust me. And I was cop, have a PhD, and teach criminal justice. United States v. Humphries, (4th Cir. 2004):
The Supreme Court has repeatedly admonished that the standard for probable cause is not “finely tuned” or capable of “precise definition or quantification into percentages.”
Well that's not helpful. But yeah, it's a bit unfair to overly fault cops for not meeting a definition you can't define.

But, uh, what is probable cause. I'm telling you there's no answer. But a working definition I've used and cops will know ("reason to believe...") is actually not that good because "reason to believe" implies more than 50/50 chance. It's less than that! Dig this, from US v. Humphries (4th Cir. 2004):
Similarly, we have stated (United States v. Jones, 1994) that the probable-cause standard does not require that the officer's belief be more likely true than false.
Well, damn. That was sort of news to me. (Which is why I'm posting this.)

So less than 50 percent is clear. And "reasonable suspicion" is clearly (though only partially) defined as "less than probable cause." So we're talking a pretty low bar here. But I mention in terms of the low "hit rate" cited in the DOJ Report. What's good enough? 10 percent? 25 percent? It depends. But if the hit rate gets anything close to this level, you can't argue there's prima fascia evidence of unconstitutional policing.

And the argument that arrests are bad because charges are dropped? It's absurd. Along with bureaucratic BS (prosecutors march to a much different drummer than cops), the standard for conviction is "beyond a reasonable doubt." The standard for arrest is "probable cause" (which isn't even "more likely true than false." So of course good legal arrests will be dropped.

On top of that, most low-level offenses are abated by arrest. You don't actually prosecute people for loitering and trespassing on a stoop. A loitering arrest isn't bad because it's not prosecuted. It's never prosecuted. And for such minor offenses, officer have pretty low motivation to write a good report, since it really just doesn't matter.

[In my intro classes, I just want students to know that "reasonable suspicion," based on Terry, is the legal standard to justify a stop and/or frisk; probable cause, based on the 4th Amendment, is the legal standard needed for a search or arrest. And even this is a tough sell.]

[Thanks to somebody else for all the research and some of the writing here]


Tombstone courage said...

Terry v. Ohio is all I was ever concerned about, not the batting average. I have a doctorate and was a cop for two decades. Terry isn't hard to articulate in a courtroom. Sometimes you lose at probable cause hearings, but if you pay attention, you learn. You learn over time and experience. A real working cop will spend thousands of hours in a courtroom during his career. He or she will learn to read situations, hopefully. The opportunity is there.

aNanyMouse said...

Typo alert: "On top of that, most low-level offense are abated are (on?) arrest."

How much diff is there between this "reasonable suspicion" stuff, and Justice Stewart's famous quip about problems in defining porn: "I know it when I see it"?
It's a drag that SCOTUS has been at it for decades if not centuries, but still can't give cops more guidance than this.

Moskos said...

Tombstone, yeah, of course in reality you just develop a working definition and understand what you need to do and what the prosecutor wants and will or won't accept.

But most people don't realize this. And I often try and get at is the disconnect between academic/textbook descriptions of constitutional issues and how they actually work out on the street.

When the DOJ says police practice is "unconstitutional," what does that actually mean?

I've done a fare bit of research with police in other countries. And it's kind of funny to go there with the sacrosanct idea that they can't stop somebody without "reasonable suspicion" or arrest somebody without "probably cause." Cops look at you funny.

I'm all for our constitution. But it is just a piece a piece of paper. Minor constitutional violations can be gray. And even when on the wrong side, it's worth pointing out that such violations are "mala prohibita" more than "mala in se."

Tombstone courage said...

Yes, I think it is great that you are trying to convey Terry v. Ohio to a civilian audience. I understand how difficult it is to explain. A veteran told me if you have reasonable suspicion, probable cause, you make the arrest and your done. What the courts do, you can't control and don't personalize it.

When you are in court, the arresting officer is under oath, but the defense attorney is not! Had a case where a cop was shot and killed. In opening remarks the defense attorney said she would show the cop was killed by his partner, but never revisitrd it or introduced evidence. A huge insult to the living partner in the courtroom. Perfectly legal though. You have to have a thick skin. So if a judge tosses your dope pinch, it is nothing to lose sleep over. Some police believe judges will toss cases to relieve jail overcrowding. You do your job, put the paperwork in, it is in the hands of the system. You can't take it personally, but you can learn by it.

Moskos said...

Well said.

I honestly did not know attorneys are not under oath. Interesting, though I'm not quite sure why.

So how do cops managed to not take things personally while also kind of giving a shit? At some point you need a balance the two, right? (Otherwise you'd be lazy or corrupt.) So at some point one or the other is going to be a bit of a veneer. But the last thing you want is a cop who both doesn't give shit *and* takes things personally!

Tombstone courage said...

Try to accept the fact that the sheep doesn't understand the sheepdog. That way you can accept taking some shit. If you are lazy or complacent, you can get crippled, killed or fired, or even jailed. So, don't be complacent. Try to do the job as bedt you can.
A special forces guy said, "every day is selection day". Act like you are trying out for selection every day. Don't believe you "got it made" because you passed the academy and probation and now you have the job, get better.

The reason the attorney is not under oath is because they do not testify. The prosecutor has to meet a burden of proof beyond a reasonable doubt.
The defense attorney must create a shadow of doubt. They do not have to be sworn because they are free to present any argument. Thus, the attorney can concoct, "affluenza" , or "his partner killed him", etc. IF the jury will buy it, then that's it.
A defense attorney once questioned me on the stand, he said,"before you answer, let me remind you are sworn under oath." I answered, "I understand that I am under oath, and you are not." There was nothing he could say. The grandstanding gambit backfired in front of the jury.

Lastly, I was told that what happens in a courtroom isn't a contest or competition with wimnerd and losers. When justice is served, everyone in the process wins.