Presentation on theme: "Forensic Death Scene Investigation Presented by Darrell Thompson Chief Forensic Death Investigator Tarrant County Medical Examiner’s District."— Presentation transcript:
Forensic Death Scene Investigation Presented by Darrell Thompson Chief Forensic Death Investigator Tarrant County Medical Examiner’s District
DEATH SCENE INVESTIGATION Introduction Death scene investigation is a crucial part of the overall function of the Medical Examiner’s Office. The scene investigation is vital to the final ruling as to the cause and manner of death.
INITIAL REVIEW OF THE KNOWN FACTS Interview The lead police investigator Witnesses knowledge of the facts and circumstances prior to and leading up to the death
APPROACH TO SCENE Keeping in mind all that has been learned from preliminary interviews View the overall scene prior to approaching Photograph Distant photograph depicting the entire scene and placement of the body Each direction of the compass Photograph the body, documenting any item of interest that may further the death investigation
APPROACH TO SCENE Conduct a detailed inspection of the body and the area immediately surrounding the body Any possible physical/trace evidence Collect and preserve Note overall injuries and injury patterns on the body Match the details learned from the initial interviews? If not, why?
APPROACH TO SCENE Is this the death scene Are there large open wounds and a lack of blood at the scene Could this death have occurred at a different location Observation of rigor and livor mortis Moved or shifted after death All trace evidence should be left in place on the body Wrap the body in a clean white sheet
POST MORTEM CHANGES Lividity: Describe in detail Location Blanchable Non-blanchable Contact pallor Consistent with current position of the body Match details learned from preliminary interviews Color Mottled/patchy
POST MORTEM CHANGES Rigor: Describe in detail Location on body Extent of rigidity/breakable Consistent with current position Consistent with details from preliminary interviews
POST MORTEM CHANGES Body temperature: Temperature to the touch Temperature of extremities Torso Dependent areas
POST MORTEM CHANGES DETAILS THAT MAY AFFECT POSTMORTEM CHANGES Ambient temperature Disease process (sepsis, seizures) Hyperthermia Hypothermia Drug use Physical exercise
INJURIES AND INJURY PATTERNS All readily visible injuries should be noted and documented Initial inspection, keep in mind Preliminary interviews Do the injuries correspond to the details as furnished by police investigators and witnesses? Injuries are inconsistent with the known details Review findings with the police investigator in charge and if necessary Re-interview witnesses, in an attempt to establish a reason for the inconsistency. Note in detail in the investigator’s report unexplained inconsistencies
INJURIES AND INJURY PATTERNS Injuries: Describe injuries Location Type Blunt force Laceration Cut Gun shot Severity Distinguishing markings
INJURIES AND INJURY PATTERNS Document the corresponding Objects Weapons Document details, that may explain the observed patterns Collect as evidence Inspect the clothing for impression/marks Transferred by objects located at the scene Photograph Collect
MOTOR VEHICLE ACCIDENTS Full description of the vehicles Damage, severity of damage Intrusions into the passenger compartment Vehicle structures Foreign objects Mechanical condition Describe all tire marks at the scene including Skid/brake Straight line from application of brakes Yaw Curved path faster than the tire can handle Scrub Irregular at point of impact/immediately after Length Relation to incident
MOTOR VEHICLE ACCIDENTS Debris pattern Impact point Gouge marks Debris from vehicles Dust or dirt dislodged at time of impact Seat belt use, type, and condition Air bag information/injuries Attempt to determine the decedents seating position Dicing injuries Secondary impact points
MOTOR VEHICLE ACCIDENTS Photograph The entire accident scene Each direction of the compass where possible Close ups of the vehicles and decedent(s) Interior of the vehicles Secondary impact causing visible injuries to the decedents Motorcycle information Helmet
MOTOR VEHICLE ACCIDENTS Charges which may be filed in connection with the death Are any drugs or alcohol involved in the death
AUTO PEDESTRIAN Injuries and injury patterns Consistent with damage to vehicles Impact points Body/vehicle Injury impression pattern Suspected point on vehicle that may have caused the pattern/injury. (Grill, Emblem, etc) Secondary impacts Body/head contact with vehicle Body with pavement/fixed object Consistent with witness statements
SHOOTING DEATHS Location of wounds Type of wound Powder marks, stippling Weapon Caliber Ownership Secondary impact points if the bullet exited the body Directionality consistent with the known details
SHOOTING DEATHS: Ammunition Remaining rounds in weapon Rotation of cylinder (revolver) Live Spent Under hammer Possible blood spatter patterns on weapon Consistent with physical evidence and known details GSR swabbing of shooter/witness Protect decedent’s hands with paper bags
STABBING DEATHS Location of wounds Defense wounds Attempt to determine the type of weapon used Injury patterns Blood patterns Blood spatters Location of initial injury versus location of body blood stains in a separate area from the location of the body
HANGING Inspect the knot Type How tied Running/fixed Point of suspension How affixed Distance from ground/floor Evidence of previous suspensions Autoerotic Position of body Platform
HANGING Autoerotic Mirror, positioned for self viewing Pornographic material/video Failsafe system Nudity Video camera Lingerie Evidence of previous suspension Position of body Contact with floor/ground Elevated
ELECTROCUTION Source of power Voltage Voltage of the available electrical source Ground Fault Interrupter Equipment Power tools Extension cord
ELECTROCUTION Equipment Assure the power has been turned off Closely inspect it for damaged or exposed wiring Electrical arcing Inspect extension cords Location Clothing Shoes Moisture Grounding points for the decedent Evidence of arcing Entry/exit wounds
FALLS Reason for the fall Intentional (suicide) Slip (accidental) Pushed (homicide) Details of fall Point from which the decedent fell Distance to point of impact Vertically from point of elevation
FALLS: Horizontally from point of elevation Any evidence at point of elevation Scuff marks Signs of struggle Point of impact Consistent with Accident Suicide Homicide Does the scene suggest the injuries are not due to a fall?
BLUNT FORCE TRAUMA How injuries may have occurred Injuries and injury patterns Consistent with any surrounding objects Object at the scene that may have caused the injuries Evidentiary value
DRUG RELATED Drugs or paraphernalia Location in reference to death scene Possible type of drugs involved Collection and preservation Evidence on the body that may indicate drug use Injection sites Indications of inhalation, or huffing
DROWNING Condition of the body Discoloration Bloating Washer woman hands/feet Are there visible injuries Consistent with details Sustained during submersion, or recovery of body Body impacting objects in moving water Injuries from recovery equipment. Details of circumstances surrounding the drowning.
UNEXPLAINED DEATH Unexplained death scene Review of the post mortem changes Injury patterns Scene of death Review the immediate area surrounding the body for anything which may have played a role in the death Weapons Tools Power equipment Electrical lines, boxes Drugs, paraphernalia Possibility of a fall
UNEXPLAINED DEATH The death scene (location where the death occurred) should, in most cases, reveal some details as to what may have caused the death. A close inspection and photography of the scene are vital to a successful inquest.
FINALLY There is only one chance to assure a complete and thorough death scene investigation.