Forensics 3 CSI Stuff

  1. Acquire medical assistance for injured persons; find safe zones

  2. Detain any potential suspects or witnesses

  • statements from witnesses

  • video surveillance

  • anything that will help identify the criminal/extra evidence

  1. Securing the crime scene(to the greatest extent you can)

  • like a few yards in each direction

  • keep civilians outside of the crime scene

  1. Calling for additional personnel; other officers, other forensic investigators

Securing the Crime Scene:

Where the perpetrator entered and exited the crime scene(windows cracked open, open/broken doors); who did what and when(did the family open windows or did the police or the perpetrator?; was the heating or ac turned on?)

NEED to use crime scene tape; rope; or cones

Secure area where there will be the most amount of physical evidence; surrounding the crime itself is most important.

  • Tangible evidence; hair fibers, weapons, etc. Things we can test.

A detailed log is kept of all individuals who enter and exit the secured area to maintain chain of custody and ensure that no potential evidence is compromised.

Investigators should NEVER tamper or do something that even might disturb evidence or the scene(littering, smoking, vaping).

Searching the Crime Scene:

Search pattern - depends on the size of the scene and where

No overlooking evidence

Physical evidence can be from microscopic to massive

The Walkthrough—initial survey of the crime scene

  • perp’s point of entry and exit

  • indirect path to the center of the scene (avoid contaminating evidence)

  • obvious items of evidence are located and documented

  • condition of the scene—special attention to things that suggest the timing of the incident or do not appear to belong

Line/Strip

  • one or two investigator start at boundary of crime scene and search in straight lines across the other side of the crime scene

Grid

  • two or more investigator search in line patterns that overlap and are perpendicular

Spiral

  • go form outside and work your way to the center

Quad/zone

  • a crime scene is split into zones and one (or more) investigator investigates the zones

Vehicle

  • document outside; any dents scratches—and inside; glove compartment, under seats—and tires? maybe ig that’s outside

    • Do everything with valid reasoning

Recording Methods:

Photography, sketches, and notes*; ideally all three

*interviews with law enforcement officers, family, witnesses; can be recorded

Crime Scene Notes:

  • Contact information—who contacted who; where they’re from, when they were called, when they showed up, shield #; the more people you get the better

  • Who What Where When Why; preliminary case information

  • Personnel present on arrival and those being contacted

  • Observations made

    • Uniform layout/easy to read

    • Blue or Black Pen; Voice memos are fine too/typing

You can make a checklist

Digital Photography:

  • More pixels = better resolution; more detail

    • measured in megapixels

  • Should record the area in which the crime scene took place + all other areas that are relevant to the crime/where important acts took place

  • No editing the photos; even brightening it so it’s easier to see

  • Should take photos in logical progression:

    • Big range: through the door; one big photo of the room; go from corner to corner to capture a wide range of the scene; outside the borders of the scene/surrounding area; include a “visual tag” to help piece the various pictures together

    • Medium range: a picture or two of a general area; captures the idea of what happened? Evidence markers; one of the center of the scene(with the body)

    • Close up: 90 degree angle w/out evidence markers and scales; then again with scale. Then from other angles. MOST IMPORTANT are the weapons and injuries lying near the body. The surface of beneath the body should be photographed.

Videotaping Crime Scenes:

  • Must include overview, medium range, and close-up images.

    • One long continuous video, no stopping/cuts

  • Quiet videos are the best; not allowed to mute it bc that counts as alterations—you can point to evidence found instead of saying anything.

  • Photographs are still required because video photos are usually bad quality.

Crime Scene Sketches:

  • Kind of outdated but wtv

  • Clearly show layout of a crime scene

  • Illustrate the relationship between space and significant figures in the scene

    • Clarify objects and features as described in notes

  • Show measurements over long distances, topography

  • exit and entrance points

  • Start with a rough sketch—dimensions, boundaries of the scene, identity of objects, who made the sketch, NOT to scale, compass showing the north direction, the body

  • Finished sketch—drawn with CAD usually, drawn to scale and with concern and care for appearance

Collection Procedures:

  • Collect things that may have trace evidence bc you’ll never know until it’s at the lab (vacuum bag)

  • no breaking, evaporating, breaking, bending, contaminating, or scratching evidence; store in correct things

  • wear proper PPE

  • keep evidence in it’s original condition as it was found at the crime scene

  • each different piece of evidence goes into a different containers; prevents cross-contamination(ex: bullets—each bullet goes into a dif. container)

  • Forceps, plastic pill bottles, manila envelopes, sealable plastic evidence, metal cans; NOT REGULAR MAILING ENVELOPES BC IT’LL LEAK

  • Biological evidence; anything wet; should air-dry first before being packaged

Chain of Custody:

  • list of all persons who came into possession of an item of evidence, as well as when and where they were in possession of it.

Standard/Reference Sample: physical evidence whose origin is known; it can be used to compare other things to it.

Substrate Controls: materials adjacent or close to areas where physical evidence has been deposited.

Submitting Evidence:

  • directly to lab by mail-in-order or mail shipment

  • mostly all evidence collected will be submitted; case information on the evidence is appreciated and recommended

Search and Seizure Protocols:

  • The removal of any evidence from a person or from the scene of a crime must be done in conformity with Fourth Amendment privileges

  • Search and Seizure without a warrant is okay in 4 circumstances

    • Emergency circumstances(natural disasters?)

    • A need to prevent the immediate destruction of evidence

    • The person arrested says it’s fine (verbal consent)

    • A search of a person and property within the immediate control of the person, provided it is made incident to a lawful arrest

Mincey vs. Arizona

  • legality of a 4-day search

  • evidence was illegally seized bc there was no warrant

  • admitted to killing a man, but the drugs found were born from forced entry

  • evidence was deemed inadmissible

Michigan vs. Tyler

  • fire destroyed a business suspected of insurance fraud.

  • evidence obtained from initial search was legal, but evidence obtained 4, 7, and 24 days after the fire were illegally seized.

  • no search warrant

  • immediately after a fire you don’t need a search warrant, but the days following you do.