Criminal Law and Procedure
Criminal Law and Procedure tests your ability to review police action for legal sufficiency, not to retry the case in the field. A sergeant must spot missing elements, weak probable cause, and procedural defects before a report or arrest moves forward.
Core standards
Arrest requires probable cause that a crime was committed and that the person committed it. An investigative detention requires reasonable suspicion, based on specific facts, that criminal activity is afoot. Searches generally require a warrant, consent, a recognized exception, or lawful incident to arrest. Consent must be voluntary; custody plus interrogation triggers Miranda warnings. For California peace officers, Penal Code § 835a controls use-of-force justification and requires necessity under the totality of circumstances, with de-escalation and alternatives where feasible. Offense elements matter: a report that recites a conclusion (“the subject resisted”) without the acts, words, and officer warnings may not support the charge.
Worked example
An officer reports a traffic stop: “Vehicle looked suspicious, so I stopped it and saw a gun.” The sergeant should not approve the narrative as written. The report must state the observed Vehicle Code violation or other specific facts supporting reasonable suspicion. Reasoning: “looked suspicious” is a conclusion; the stop rises or falls on articulable facts. The sergeant directs a supplemental report before the case is filed.
Traps that cost marks
- Treating reasonable suspicion and probable cause as interchangeable.
- Accepting conclusory report language.
- Missing custody/interrogation issues.
- Ignoring search exceptions or consent scope.