Investigations, Evidence, and Problem Solving
Investigations and evidence
A case is built from lawful observations, statements, physical evidence, and documentation. Learn the evidence categories-testimonial, documentary, real/physical, and demonstrative-and the chain of custody: every transfer of an item should be recorded so a later challenge cannot show tampering or contamination. Crime-scene priorities are life safety, scene security, preservation, documentation, collection, and packaging. Interviews are non-custodial fact-finding; interrogations of a custodial suspect require Miranda. Eyewitness identification should use fair, unbiased procedures-avoid suggestiveness in lineups and show-ups.
Problem solving
Problem-oriented policing uses SARA: Scanning (identify and prioritize), Analysis (who, what, when, where, why), Response (tailor an intervention), and Assessment (did it work?). This is a favorite exam distinction: SARA is not a use-of-force model.
Traps
- “Any statement by a suspect is admissible” - voluntariness and Miranda matter.
- “Chain of custody requires every person to testify” - it requires a documented, unbroken record.
- “A show-up is always illegal” - a show-up can be permissible if conducted promptly and not unnecessarily suggestive, but it is scrutinized.
- Confusing interview (information gathering) with interrogation (designed to elicit incriminating statements).
Worked example
You recover a phone at a burglary scene. Photograph it in place, note its location, collect it with gloves, package it, log who collected it and each transfer, and submit it to property/evidence. If it is later searched, document the legal authority-warrant, consent, or exception.