1. Injury and Death Investigation
Chapter 9
Injury and Death Investigation

2. LEARNING OBJECTIVES
Describe the four motivational models for classification of homicide
Identify the investigator's responsibilities when responding to the scene of a suspected homicide or assault
Describe the investigative tools and equipment necessary to process a homicide crime scene
Discuss the various stages of the medical legal examination including the autopsy
Recognize the potential evidentiary value of gunshot wounds, incised stab wounds, puncture wounds, lacerations, and defense wounds
Discuss the roll of the forensic entomologist in determining time of death
Identify the characteristics of strangulation wounds
Recognize wounds inflicted with a blunt object

3. LEARNING OBJECTIVES continued
Discuss information used by investigators to distinguish between homicide and suicide
Be familiar with the methods and evidence involved in suicides
Discuss the characteristics of various poisons and their associated manifestations
Outline the facts that need to be determined in the investigation of fire deaths
Discuss the seven major components which indicate a serial murderer is operating in a jurisdiction
Discuss the ways in which a cold case murder investigation may be started

4. HOMICIDES
Excusable Homicide: The difference between justifiable homicide in that one who commits an excusable homicide is at some degree at fault but the degree of fault is not enough to constitute a criminal homicide.
Felonious Homicide: Treated and punished as crimes and typically fall into two categories: murder and manslaughter.
Justifiable Homicide: The necessary killing of another person in the performance of a legal duty or the exercise of a legal right when the slayer was not at fault.

5. MOTIVATIONAL MODELS FOR CLASSIFICATION OF HOMICIDE
Criminal Enterprise Homicide
Criminal enterprise homicide entails murder committed for material gain
Personal-Cause Homicide
Personal-cause homicide is motivated by a personal cause and ensues from interpersonal aggression

6. MOTIVATIONAL MODELS FOR CLASSIFICATION OF HOMICIDE continued
Sexual Homicide
A sexual element (activity) is the basis for the sequence of acts leading to death
Group-Cause Homicide
Two or more people with a common ideology sanction as act, committed by one or more of the group's members, that results in death

7. RESPONDING TO THE HOMICIDE SCENE
When responding the investigators should:
proceed with deliberation not reckless speed
be observant for a fleeing suspect
be suspicious of vehicles leaving the scene
be alert to an individual trying to hide

8. Confirm or pronounce death
INVESTIGATOR’S RESPONSIBILITIES UPON ARRIVAL AT THAT SCENE OF A HOMICIDE
Scene safety
Determining scene safety for all investigative personnel is essential to the investigate process
Confirm or pronounce death
Appropriate medically trained personnel must make a determination of death prior to the initiation of the death investigation

9. Participate in scene briefing with attending agency representatives
INVESTIGATOR’S RESPONSIBILITIES UPON ARRIVAL AT THAT SCENE OF A HOMICIDE continued
Participate in scene briefing with attending agency representatives
Scene investigators must recognize the varying jurisdictional and statutory responsibilities that apply to individual agency representatives
Conduct a scene walk-through
Conducting a scene “walk-through” provides the investigator with an overview of the entire scene

10. Investigative Tools and Equipment
The following is a partial list of the tools and equipment necessary for conducting an appropriate crime scene investigation in homicide cases:
gloves
Writing implements (pens, pencils, markers)
Flashlight
Body ID tags
Cameras (35-mm, video, Polaroid) w/extra batteries, film, tapes, etc.
Investigative notebook (for scene notes, etc.)
Measurement instruments (tape measure, ruler, rolling measuring tape, etc.)
Official identification (for yourself)
Watch

11. INDIVIDUAL OBSERVATIONS USED TO ESTIMATE TIME OF DEATH
When used together the following individual observations of a body may be used to estimate the time of death
body temperature
rigor mortis
livor mortis
decomposition changes
stomach contents

12. Forensic Entomology
Body Area from Which to Collect Insects

13. Forensic Entomology
Areas of Skeleton Most Likely to Harbor Insects

14. EVIDENCE FROM WOUNDS Firearm Wounds Firearm residues
When a bullet strikes a body, the skin is first pushed in and then perforated while in the stretched state
Firearm residues
Detecting firearm residues on the hands of an individual may be of great importance in evaluating deaths due to gunshot wounds

15. EVIDENCE FROM WOUNDS continued
Incised and Stab Wounds
Puncture Wounds
Lacerations
In an assault these wounds are caused by clubs, pipes, pistols, or other such blunt objects

16. EVIDENCE FROM WOUNDS continued
Defense Wounds
Defense wound are suffered by victims attempting to protect themselves from an assault, often by a knife or club
Strangulation Wounds
Ligature strangulation. The pressure on the neck is applied by a constricting band that is tightened by a force other than the body
Manual strangulation. Pressure of the hand, forearm, or other limb against the neck, compressing the internal structures of the neck

17. A BULLET PENETRATING THE SKIN
When a bullet penetrates the skin:
the skin is pressed inward
the skin is stretched and perforated
the skin then returns to its original position
(Source: Barry A. J. Fisher, Techniques of Crime Scene Investigation, © 1992, reproduced with permission of copyright owner, CRC Press, Boca Raton, Florida)

18. Close and Distant Shots
Firearm Discharged at Close Range

19. Are inflicted with knives or razors
INCISED WOUNDS
Typically bleed a lot
Are inflicted with knives or razors
Are narrow at the edges and gaping in the middle
(Courtesy Federal Bureau of Investigation)

20. COMMON TYPES OF WOUNDS Type of Wound Characteristics
Firearm: Contact (muzzle against body)
Close (less than 18 inches)
Distant (18 inches or more)
No blackening around entry; star-shaped, often with flaps directed outward
Blackening around entry; grains of powder and deposits of powder residue
None of the above characteristics appear
Incised
Cutting wound inflicted with sharp-edged instrument, wound typically narrow at ends and gaping in middle with a great deal of blood
Stab
As above; manner in which knife is thrust into and pulled out of body can result in wounds of different shapes made with same knife
Puncture
Can be caused by ice picks, leather punches, and screwdrivers; result in small wounds with little or no blood
Lacerations
Open, irregularly shaped wounds, caused by clubs, pipes, pistols and other blunt instrument wounds accompanied by bruising or bleeding
Defenses
Commonly found on palms of hands, fingers, forearms
Strangulation: Ligature Manual
Mark encircling neck in a horizontal plane overlying larynx or upper trachea; sometimes broken at back of neck where hand grasped ligature; abrasions and contusions of skin not usually present
Abrasions, contusions and fingernail marks on skin

21. REASONS FOR SUICIDE
Ill health
Severe marital strife
Recent emotionally damaging experience
Financial difficulties

22. REASONS FOR SUICIDE continued
Perceived humiliation
Actual humiliation
Remorse over loss of loved one
Revenge

23. Evidence and Procedure
TYPES OF SUICIDE
Method
Evidence and Procedure
Shooting
Most commonly a gunshot to the temple; frequently no exit wound; investigators look for blood spatter, gunshot residue, and hammer-spur impressions on decedent’s hands.
Hanging
Neck is rarely broken; feet or knees are often touching the ground—only when unconsciousness occurs is full weight of body applied to noose, resulting in cutoff of all oxygen to the brain and thus death; petechial hemorrhaging in eyes common
Ingesting pharmaceuticals
Interviews with relatives, friends, neighbors can help determine whether death is accidental or suicidal; especially difficult because of possible unexpected interactions among drugs
Drowning
Chest cavity and lungs distended and soggy; heart flabby, with right side dilated and filled with dark red fluid; hemorrhaged mastoid cells in ear; water in stomach and duodenum; algae in body; parts of lips, ears, and nose often eaten away
Cutting
Investigators look for hesitation marks—series of lesser wounds in general region of fatal wound; self-inflicted throat wounds deep at point of entry, shallow at terminus; not unusual to see a series of cuts on different parts of the body
Ingesting poison
Mat be signs of vomiting & severe damage to lips, tongue, and mouth; victims may employ second means of suicide because death does not occur rapidly; search for poison container critical; details under “Pharmaceutical,” above, also apply
Inhaling gas
Carbon monoxide, most common, causes skin to turn bright red
Jumping
Witness interviews and assessment of victim’s predisposition to suicide critical
Intentionally crashing automobile
Usually a single occupant speeding into an off-road obstacle; lack of skid marks; shoe-sole imprints from gas and brake pedals sometimes useful

24. FACTS TO BE DETERMINED IN FIRE DEATH INVESTIGATIONS
Coordination and Cooperation
Coordination of and cooperation between police and fire investigators are of paramount importance in the successful investigation of any questioned fire
Degrees of Burning
Burns are medically classified into four types
Identification of Remains
Because fire destroys human tissue, identification of the remains may be especially difficult
Scene Considerations
As with any physical evidence, burned bodies must be sketched, measured, and photographed

25. FACTS TO BE DETERMINED IN FIRE DEATH INVESTIGATIONS continued
Examination of the External Body
The body of the deceased should be examined in detail both at the scene and again at the morgue
Examination of the Internal Body
Soot, other debris, or burning in the air passages
Toxicology Examination
The pathologist should take samples for later examination by a toxicologist
Histologic Examination
Microscopic examination of tissues is also an important part of the postmortem examination

26. FACTS TO BE DETERMINED IN FIRE DEATH INVESTIGATIONS continued
“Flash” Fires
Concentrated burns in one area of a body may indicate the nature and cause of death
Motives of Fire Deaths
In fire deaths, various motives should be kept in mind by investigators
Recording the Scene
Photographs of the body in its original position and of the room or area in which it is found

27. For the law enforcement community, “serial murder” usually refers to:
sexual attacks
resulting death of young women, men, or children
committed by a killer who tends to follow a distinct physical or psychological pattern.

28. Serial Murder continued
There are seven major components that may serve as flags to alert investigators to the possibility that a serial murderer is operating in their jurisdiction:
One or more individuals (in most cases, males) commit a second murder and/or subsequent murders.
There are generally no prior relationships between victims and attacker (if there is a relationship, it will be one that places the victim in a subjugated position relative to the killer.
Subsequent murders occur at different times and have no apparent connection to the initial murder.

29. Serial Murder continued
Subsequent murders are usually committed in a different geographic location.
The motive is not for material gain; it is for the murderer’s desire to have power or dominance over his or her victims.
Victims may have a symbolic value for the murderer; and/or they may be perceived as lacking prestige, being unable to defend themselves or alert others to their plight, or being powerless given their immediate surroundings.
Victims typically include vagrants, the homeless, prostitutes, migrant workers, homosexuals, missing children, single women (out by themselves), elderly women, college students, and hospital patients.

30. NATIONAL CENTER FOR THE ANALYSIS OF VIOLENT CRIME (NCAVC)
Designed to form a partnership among federal, state, and local law enforcement agencies in the investigation of potentially related, unsolved violent crimes

31. Cold Case Homicides