1. Chapter 1 Investigating the Crime Scene

2. Objectives In this chapter you should gain an understanding of: – The steps taken to preserve a crime scene – Documentation of the crime scene – Ways to systematically search the crime scene – Methods for collecting, preserving, identifying, packaging, and transporting evidence – The chain of custody – The Fourth Amendment and its application to the search and seizure of evidence

3. Introduction The collection and preservation of evidence are essential for any successful criminal investigation. Physical Evidence includes any and all relevant materials or objects associated with a crime scene, victim, suspect, or witness.

4. Securing the Crime Scene The first person to arrive at a crime scene is referred to as the first responder. The first responder’s top priority is to offer assistance to any injured persons. Secondary to this is the responsibility of securing the crime scene. To safeguard evidence and minimize contamination, access must be limited.

5. Identifying, Establishing, Protecting, and Securing the Boundaries Initial boundary should be larger than the scene. Responders should document all actions and observations as soon as possible. Responders must ensure that physical evidence is not lost, contaminated, or moved. Physical evidence should be preserved for later identification, collection and submission.

6. What should be documented? The first responder should document the following: – The state of the scene upon arrival. – Existing conditions upon arrival. – All personal information concerning witnesses, victims, and suspects. – Actions and statements of witnesses, victims, suspects and all other personnel who entered or exited the scene. – Any items that may have been moved and who moved them.

7. Controlling Access A single path into and out of the scene should be created. All personnel at the scene should be identified and their names recorded in case investigators need to interview these individuals or obtain known samples from them.

8. Crime Scene Safety Personnel who enter the crime scene should remember some common sense rules:

9. Personal Protective Equipment (PPE) LE agencies train CSI’s to comply with rules from OSHA, requiring training and appropriate PPE for the hazards they may face. Gloves: two pairs (typically nitrile). Change often. Eye and face protection: safety glasses and face shield. Inhalation hazards: dust mask, air purifying respirator or self-contained breathing apparatus. Protective Clothing: disposable synthetic coveralls and shoecovers.

10. Documenting the Scene and the Evidence Documentation at the crime scene involves four major tasks: – Note taking – Photography – Sketching – Videography

11. Note Taking Note taking begins with the first responder. Notes are the principal way of refreshing one’s memory. Audio recording may be used to supplement the written notes.

12. Photography Systematic series of photographs

13. Photo Log Each photo taken at a crime scene must be recorded in a photo log. This log should record: – Date and time – Camera settings – File name and exposure number – Type of shot (overall, midrange, or close-up) – Distance to the subject – Brief description of subject matter photographed

14. Sketching Sketches are made to document perspective and distance which would not be accurately reflected within photographs. Purpose is to accurately record distances between objects at the scene. Rough sketches are produced at the scene. Finalized sketches are produced from information contained on rough sketches.

15. Sketches (cont.) Sketches must include: – Case identifier – Date, time, location – Weather and lighting conditions – Name of the sketch – Identity and assignments of personnel – Measurements, Dimensions, Positioning and Layout – Key or legend – Orientation – Scale

16. Measurement Techniques Triangulation method: Baseline method: Polar coordinate method:

17. Videography Video should complement, not replace, photographs. Video allows investigators, witnesses, jury, etc., to return to the scene as often as necessary, in a realistic manner. The simultaneous audio track can provide added benefit, at times.

18. Systematic Search for Evidence All searches should be systematic and thorough.

19. Systematic Search for Evidence Common search pattern types:

20. Recognition of Physical Evidence The ability to recognize what is and what is not evidence is a skill that is best learned through experience.

21. Types of Evidence Questioned sample: (Unknown sample) collected at crime scene. Known sample: (Reference or Standard sample) collected from a known subject or object for comparison purposes. Individualization: process of proving that a particular unknown sample is unique Trace evidence: extremely small and often microscopic evidence.

22. Packaging Evidence Type of packaging chosen depends on type and amount of evidence collected. Goal is protection and preservation of evidence. Package each item separately Paper is preferred packaging

23. Packaging Evidence (cont.) How to fold a piece of paper to make an evidence container (especially for trace evidence collection)

24. Submitting Evidence to the Crime Laboratory Evidence may be submitted via mail or personal delivery. Be aware of mailing restrictions (guns, ammo, hazardous materials, etc.) Each shipment must include an evidence submission form.

25. Chain of Custody Chain of custody is the written chronological record of each person who had an item of evidence in his/her possession. The prosecution must account for this from discovery to collection to analysis to storage to transfer, throughout the entire process, including court proceedings and appeals. Begins with the original discoverer.

26. Reference and Control Samples Some evidence requires the collection of a reference sample in order to ascertain its origin or identification. Substrate control samples may also be collected. These are samples collected in the proximity of evidence or reference sample collections.

27. Criminal Evidence and the Fourth Amendment The seizure of all evidence must be done in compliance with the Fourth Amendment. Search warrants are legal court orders which, upon establishment of probable cause, permit an exception to the Fourth Amendment. Arrest warrants are legal court orders declaring there is probable cause to believe that the person to be arrested has committed a crime.

28. Exceptions to the Fourth Amendment Border searches Consent searches Search incident to arrest Plain View Emergency/Exigent Circumstances Open Fields Stop and Frisk Vehicle Inventories

29. The Supreme Court and the Fourth Amendment Mincey v. Arizona (1978) Michigan v. Tyler (1978)