One of the standards used in criminal cases is “reasonable suspicion”. This standard applies to police encounters short of an actual arrest. The most common encounter is a traffic Stop. Since your freedom is being infringed on – even if just for a little while – there must be a reason to do so. The standard the courts will apply is “reasonable suspicion.” So what does that mean?
Here’s an excerpt from an opinion by the Houston Court of Appeals in State v. Bernard, 503 S.W.3d 685 (2016):
A warrantless automobile stop is a Fourth Amendment seizure analogous to a temporary detention, and it must be justified by reasonable suspicion. Berkemer v. McCarty, 468 U.S. 420, 439, 104 S.Ct. 3138, 82 L.Ed.2d 317 (1984); see Derichsweiler v. State, 348 S.W.3d 906, 914 (Tex. Crim. App. 2011). The reasonableness of a temporary detention is determined from the totality of the circumstances. Leming, 493 S.W.3d at 562; Zuniga–Hernandez v. State, 473 S.W.3d 845, 848 (Tex. App.–Houston [14th Dist.] 2015, no pet.). If an officer has a reasonable basis for suspecting a person has committed a traffic offense, then the officer legally may initiate a traffic stop. Id. Reasonable suspicion is present if the officer has “specific, articulable facts that, combined with rational inferences from those facts, would lead [the officer] reasonably to conclude that the person ... is, has been, or soon will be engaged in criminal activity.” Derichsweiler, 348 S.W.3d at 914; Zuniga–Hernandez, 473 S.W.3d at 848. “An officer's stated purpose for a stop can neither validate an illegal stop nor invalidate a legal stop because the stop's legality rests on the totality of the circumstances, viewed objectively.” Id.
Unless you’re a lawyer, you probably wonder what all that means. Basically, it means the officer has to have a reason he can put into words as to why he thinks you committed an offense. Speeding cases are pretty easy when radar is involved – "I was using my radar, and clocked the car going XX." Most traffic offense are also pretty simple – "he didn’t use a turn signal when changing lanes," or making a turn, or didn’t stop at a stop sign.
The harder cases (and better cases for defense lawyers) are when the stop involves some subjective determination – such as following too close, or failing to signal 100 feet before turning. Generally those decisions are based on estimates – which must be reasonable.
There also can be issues when the interpretation of a statute is involved. An example is a case I had where the defendant was charged with failing to signal a lane change, even though he was in a turn lane. We won the motion to suppress because the judge found that wasn’t a violation (after having to dig up some really obscure document on lane markers).
Something people are sometimes surprised to learn is that the subjective intent of the officer is not an issue. For example, an officer might see you driving down the highway and think you look like a drug dealer so he starts following you. He cannot stop you because of his suspicions, but if you commit a traffic offense while he’s following you that’s fair game. It also can go the other way. The officer may believe you’ve committed a certain offense, but if his interpretation of the law is wrong, that doesn’t validate the stop.
In case you’re wondering, reasonable suspicion is not enough to justify an arrest. There is higher burden required to actually place you in custody. I’ll address that in another question.
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