The Crime Scene (2) Old Crime

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What Is A Crime Scene? A dynamic environment which begins to change immediately after the criminal action occurs The longer the interval between the crime and the investigation, the less the scene resembles the original

Crime Scene The investigator becomes part of the crime scene –processing the scene will alter it –alterations can be minimal or major –alterations can be deliberate or unconscious

Crime Scene Don'ts No Eating No Drinking No Smoking

Who is at the Scene? The Detective –law enforcement representative –usually in charge of the crime scene –takes notes The Criminalist or Evidence Technician (Various specialties) –collects evidence The Photographer –documents the scene before anything is removed –may use both still photography & video

Who is at the Scene? Latent Print Analyst –looks for both visible and invisible (latent) fingerprints Firearms Expert –may be called if a firearm is believed to have been discharged –Collects and examines bullets, shells, casings, wads Bloodstain Pattern Expert –measures & documents patterns at scene –takes photos for later study

Who is at the Scene? Coroner/Medical Examiner –declares a body to be dead –transports body to morgue for autopsy & evidence collection –medical examiner holds a medical degree appointed to position –coroner need not have a medical degree often an elected office

Crime Scene Processing 1. Establish Legality of Search- Warrants!!!!! –4 th, 5 th, 6 th, 14 th Amendment Protections 2. Secure/Isolate Scene while giving medical assistance –Encounter Site –Attack Site –Victim Dump Site –Vehicle Disposal Site 3. Search Scene and Define its Borders

Crime Scene Searches Lockerbie Bombing 35 S.U. students killed by terrorist bomb on Dec (Pan Am Flight 103). Crime Scene spread over 845 sq. miles of Scotland.

Search Patterns Spiral Zone Line Grid

What Search Type?

Buried Sites Follow Archeology Protocols

Levels of Search Phase 1 –Examine scene with EYES ONLY –Mark potential evidence –Photograph –Draw –Take Notes –Measure distances of evidence from fixed points

Evidence Team Personnel Duties and Responsibilities Sketch Preparer Diagram area of scene (incl. orientation) Rough sketch - accurate dimensions, orientation and location of evidence (from a fixed point) Finished sketch - aesthetic appearance (usually done later sometime w/ CAD) Set forth major items of evidence on sketch (with scale) Make measurements (double check)

Crime Scene Sketch

Evidence Team Personnel Duties and Responsibilities Sketch Preparer Finished Sketches

Evidence Team Personnel Duties and Responsibilities –Photographer and Photographic Log Recorder Photograph entire scene (before and after entered) Photograph victim, crowd, vehicles Photograph evidence before it’s moved (including fingerprints, casts, etc.) Photograph evidence both in wide view (position at scene) and close-up (with scale) Possible use of video recording (does not replace still photography Prepare photographic log

Capture Crime Scene

Wide angle lenses are used to distort the truth or emphasis it

Details preserved

3D Laser Scanning

Documentation is Key! 1.Description of item 2.Location in crime scene from which collected 3.Case number 4.Date & time collected 5.Signature or initials of collector

Crime Scene Processing Phase 2 –Collect and store evidence appropriately –Also collect control samples Paper bags Tweezers+ToolsPill bottles Manila envelopes Empty Paint Cans Swabs Vacuum Body Bag

Packaging Evidence Prevents any change after collection Proper identification Prevents cross contamination (separate packaging) Preserved intact (e.g., blood on clothes) Crime scene safety

What determines the type and manner of collecting and preserving physical evidence? The nature of the evidence

Crime Scene Processing Large areas many be sawed out and transported Cars removed to lab garage

Crime Scene Search Phase 3 (most intrusive) –Open drawers –Turn over items in scene –Look in clothes –Develop latent prints –Spray Luminol –Remove carpet and wall sections

On Site Analysis Visible prints on immovable objects will be photographed Latent prints (invisible) will be dusted or fumed for visualization –lifted –Photographed Presumptive Tests –blood –semen –hydrocarbons (arson)

On Site Analysis Bullet trajectory –best established at crime scene –direct measurement of distances between holes –investigator can stand in the 3-D space to get sense of relationship of the holes to one another Bloodstain pattern –measurements of pattern help establish the direction & angle of impact –standing in 3-D space gives useful impression of how the pattern was created

Chain of Custody Validates authenticity, validity, integrity of evidence

Non-biological Impurities –storing improperly sealed volatiles in the same physical space cross-contamination –crime scene investigator tracking soil from outside a crime scene into crime scene or from one scene to another

Non-biological Impurities –chemicals which also react in a test paraffin test for nitrate residue on hands (firearm discharge) –tobacco & fertilizer give positive tests

Non-biological Impurities –chemicals may be introduced in an attempt to locate evidence dusting for fingerprints Luminol for detecting non-visible blood accommodations can be made in analysis & interpretation since the presence of these materials is known

Biological Impurities –Microorganisms Can destroy a sample overnight –bacteria & fungi grow well in warm moist conditions –microorganismal spores are ubiquitous –prevented by drying & freezing (sterile lab equipment) –Non-human physiological substances generally no effect on human biologicals marker systems for human protein or DNA –Human physiological substances if source is known a substrate control can be incorporated into the analysis

Crime Scene Safety Infectious materials –Wear gloves, have biohazard bags, shoe covers, Kleengard suits and masks, disposable writing instruments

Crime Scene Safety Sharps –Be alert and once encountered they are packaged

Crime Scene Safety Explosive Scenes Boston Marathon Bombing A Meth Lab

CHE 113 CHE Crime-Scene Reconstruction Step 1 - State problem - type of crime and the legal elements. Step 2 - Collect data - - records checks and police checks, interview victim, witnesses, and suspects, try to get additional witnesses and comparison samples from suspects Step 3 - Form a hypothesis - look at all evidence - determine motive and possible suspects Step 4 - Test hypotheses - evaluate how truthful and reliable the stories are, weigh their stories against the physical evidence Step 5 - Follow up the most promising hypotheses (theories) Step 6 -- Draw conclusions - supported by court-admissible evidence leading to the arrest, prosecution, and conviction of the offender.

CHE 113 CHE Crime-Scene Reconstruction Was there more than one person involved? How was the crime committed? Reconstruction supports likely sequence of events by the observation and evaluation of physical evidence and statements made by witnesses and those involved with the incident Reconstructions can play a vital role in aiding the jury to arrive at an appropriate verdict.

CHE 113 CHE Crime-Scene Reconstruction Saferstein “Criminalistics”

CHE 113 CHE Kennedy Assassination

CHE 113 CHE Homicide:Rape:Robbery: Burglary: 1- focus on deceased 1- focus on victim1 - modus operandi 1 - focus on scene 2 -crime scene 2 - medical reports2 - crime scene 2 - records check 3 - crime lab 3 - crime scene3 - police records 3 - property check 4 - usual suspects Source: adapted from Gilbert, J. (1980) Criminal Investigation. Columbus: Merrill.