Forensic Science Crime Scene Investigation Part II – The Investigation Team & Collecting Evidence

Crime Scene Team A group of professional investigators, each trained in a variety of special disciplines Team Members: First police officer on the scene Medics (if necessary) Investigator (s) Medical examiner (if necessary) Photographer &/or field evidence technician Lab experts

Crime Scene Team Lab experts: Pathologist Serologist DNA expert Toxicologist Forensic odontologist Forensic psychologist Forensic anthropologist Forensic entomologist Firearm examiner Bomb & arson expert Document & handwriting expert Fingerprint expert

Investigators “ The wise forensic investigator will always remember that he must bring all of his life experiences and logic to find the truth. This means common sense, informed intuition, and the courage to see things as they are. Then he must speak honestly about what it adds up to.” - Dr. Henry Lee Chief Emeritus for Scientific Services and the former Commissioner of Public Safety for the state of Connecticut

First Officer at the Scene A Assess the crime scene D Detain the witness A Arrest the perpetrator P Protect the crime scene T Take notes

Initial Response/ Prioritization of Efforts Arriving at the Scene: Initial Response/ Prioritization of Efforts Initial response and receipt of information Safety precautions Emergency care Secure and control persons at the scene Establish and preserve scene boundaries Transfer control of the scene to the investigator (s) in charge Document actions and observations at the scene

Preliminary documentation & Evaluation of the Scene Conduct scene assessment Conduct scene “Walk-Through” and initial documentation

Processing the Scene Determine team composition Ensure contamination control Document the scene Prioritize collection of evidence Collect, preserve, inventory, package, transport, and submit evidence

Completing and Recording the Crime Scene Investigation Establish crime scene debriefing team Perform final survey of the crime scene Documentation of the crime scene

Eye Witness “Perception is reality.” As a result, an eye witness may not be the best source of crime scene information. A police composite may be developed from the witness testimony by a computer program or forensic artist. Faces Composite Program by InterQuest

A TRUE EYEWITNESS Crazy Criminal As a female shopper exited a New York convenience store, a man grabbed her purse and ran. The clerk called 911 immediately and the woman was able to give them a detailed description of the snatcher. Within minutes, the police had apprehended him. They put him in the car and drove back to the store. The thief was then taken out of the car and told to stand there for a positive ID. With that he replied, “Yes, Officer. . That’s her. That’s the lady I stole the purse from.”

Crime Scene Search Patterns Spiral Grid Start at the center and work your way outwards Work East-West and then North-South

Crime Scene Search Patterns Strip or Line Quadrant or Zone Walk North/South line by line (almost like cutting grass) Section scene off into 4 pieces and then into smaller 4 pieces

Crime Scene Sketches c A. Couch/sofa B. Female body C. Knife Date: August 14, 2001 Criminalist: Ann Wilson Time: 11:35 Location: 4358 Rockledge Dr St. Louis, Mo. A. Couch/sofa B. Female body C. Knife D. Over turned Lamp E. Chairs F. Table G. Fireplace E c D G A E E F E

Outdoor Crime Scene Mapping Azimuth--uses a compass beam to determine the location of each piece of evidence Triangulation--uses two points at the crime scene to map each piece of evidence Coordinate or grid--divides the crime scene into squares for mapping. Suspended Polar Coordinate --for use in mapping evidence in a hole Baseline--set a north/south line and measures each piece of evidence from this line.

AZIMUTH Determines: Direction Distance Elevation

TRIANGULATION Measure from A to B and then to the evidence in a triangular shape.

Set a north/south line from a datum point established by a GPS. Coordinate or Grid Mapping Set a north/south line from a datum point established by a GPS. Measure and map the location of each piece of evidence. Then collect evidence and place in containers by grid. Make it a perfect square (4 x 4) by shooting the hypotenuse and setting in stakes every foot or meter.

Baseline Mapping Set a north/south line from the furthest most points of the crime scene. Then measure each piece of evidence from that baseline. Evidence will need a numerical measurement where the piece begins, ends and in the middle. Evidence Baseline

Suspended Polar Coordinate Measure and map each layer of evidence as you move down the hole. Use the compass readings from the top to measure degrees and a tank dipping line to measure depth.

MAPPING TECHNOLOGY The latest technology includes this Nikon Tsunami with computer. The exact location of all crime evidence can be determined and directly loaded into a computer to produce a crime scene map. Cost = $35,000 for the set.

Physical Evidence

Physical Evidence Transient Evidence--temporary; easily changed or lost; usually observed by the first officer at the scene Odor--putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke Temperature--of room, car hood, coffee, water in a bathtub; cadaver Imprints and indentations--footprints; teeth marks in perishable foods; tire marks on certain surfaces Markings – tool marks,

There are several ways (at least 7) of classifying evidence. Physical Evidence Pattern or Transfer Evidence--produced by direct contact between a person and an object or between two objects. There are several ways (at least 7) of classifying evidence. In this class, we will use: Biological Chemical Physical Miscellaneous

Physical Evidence (cont’d) Conditional Evidence --produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances within a particular event. Light--headlight; lighting conditions Smoke--color, direction of travel, density, odor Fire--color and direction of the flames, speed of spread, temperature and condition of fire

Conditional Evidence (cont’d) Location--of injuries or wounds; of bloodstains; of the victims vehicle; of weapons or cartridge cases; of broken glass, etc. Vehicles--doors locked or unlocked, windows opened or closed; radio off or on (station); odometer mileage Body--position; types of wounds; rigor, livor and algor mortis Scene--condition of furniture, doors and windows; any disturbance or signs of a struggle.

Evidence Characteristics Class -- common to a group of objects or persons Individual -- can be identified with a particular person or source. ABO Blood Typing Blood DNA Typing

Blood Semen Saliva Sweat/Tears Hair Bone Tissues Urine Feces Biological Evidence Blood Semen Saliva Sweat/Tears Hair Bone Tissues Urine Feces Animal Material Insects Bacterial/Fungal

Fibers Paper Glass Ink Soil Cosmetics Gunpowder Paint Metal Plastic Chemical Evidence Fibers Glass Soil Gunpowder Metal Mineral Narcotics Drugs Paper Ink Cosmetics Paint Plastic Lubricants Fertilizer

Physical (Impression) Evidence Fingerprints Footprints Shoe prints Handwriting Firearms Printing Number restoration Tire marks Tool marks Typewriting

Miscellaneous Evidence Laundry marks Voice analysis Polygraph Photography Stress evaluation Pyscholinguistic analysis Vehicle identification

Cadaver Dogs Dogs with a sense of smell 100 times better than humans can sometimes find what would be overlooked. They are specially trained to locate injured, lost and/or deceased individuals. They are trained as air scent dogs or article (cloth) scent dogs.

Cadaver Dogs Dogs are trained to locate human body fluids including blood, hair, teeth, urine, and semen. The dog on the left in a training exercise is trying to locate clothing with blood. www.moregionck9search-rescue.com

Cadaver Dogs Looking at a crime scene, humans would probably miss something as small as this tooth. The dog found it within minutes of searching the scene.