Probable Cause
A reasonable belief, grounded in articulable facts and circumstances, that a crime has been committed or that evidence of a crime will be found in a specific place.
Probable cause is the constitutional floor for arrest, search warrants, and charging decisions. Without it, the arrest is unlawful, the search is presumptively unreasonable, and every downstream piece of evidence is subject to suppression under the exclusionary rule.
Officer stops a car for a broken taillight (reasonable suspicion). During the stop, officer smells burnt marijuana and sees a baggie on the console. The plain-view observation plus odor crosses the threshold from suspicion to probable cause to search the vehicle.
A confidential informant makes a recorded purchase at a residence. The officer corroborates the informant’s description of the home, car, and seller. Independent corroboration of predictive detail is what converts tip into probable cause under Gates.
An anonymous caller says a man in a red jacket at a specific corner is armed. Officers find the man but observe nothing suggestive. Without predictive corroboration, the tip alone is insufficient — this is the J.L. problem.
- 01Specific, articulable facts — not conclusory statements or hunches
- 02Evaluated under the totality of the circumstances, not element-by-element
- 03Judged from the perspective of a reasonable, trained officer
- 04A fair probability — not a preponderance, not beyond a reasonable doubt
- 05Particularity: facts must tie to this person, this place, this evidence
- “Probable cause means more likely than not.” False — the standard is fair probability, a lower threshold than preponderance.
- “An officer’s training and experience alone justify the search.” False — training informs interpretation of facts, it does not substitute for them.
- “Once there is probable cause to arrest, any search is permitted.” False — search-incident-to-arrest has spatial and temporal limits (Chimel / Gant).
- “Probable cause in the warrant cures later false statements.” False — material falsehoods or reckless omissions trigger a Franks hearing.
- File a motion to suppress and demand the full affidavit of probable cause
- Cross-examine the affiant on every factual basis for the warrant
- Move for a Franks hearing if the affidavit contains false or recklessly omitted material
- Subpoena the informant file — CI reliability, prior tips, compensation
- Challenge staleness — facts must be fresh relative to the search
Verilexa runs your facts against the standard and flags the strongest suppression or impeachment angles.