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LEARNING OBJECTIVES
Name the various legal definitions related to felony assaults and homicides.
Discuss the various stages of the medico-legal examination, including the autopsy.
Describe the various postmortem changes occurring at the time of death.
Recognize the potential evidentiary value of gunshot wounds, incised and stab wounds, lacerations, and defensive wounds.
Discuss the role of the forensic entomologist in determining time of death.
Identify the characteristics of strangulation wounds. Describe wounds inflicted with a blunt object as opposed to
those inflicted with a sharp-edged instrument.
© 2012 McGraw-Hill Higher Education. All rights reserved. 2
LEARNING OBJECTIVES continued Discuss information used by investigators to
distinguish between homicides and suicides. Be familiar with the methods and evidence
involved in suicides. Discuss the characteristics of various poisons and
their associated manifestations. Outline facts that need to be determined in the
investigation of fire deaths. Discuss serial murderers, their profiles, myths and
misconceptions. Understand the role of the National Center of the
Analysis of Violent Crime (NCAVC) and the Violent Criminal Apprehension Program (ViCAP) in serial murder investigations.
© 2012 McGraw-Hill Higher Education. All rights reserved. 3
The Law
Felonious assault is also know as: Aggravated assault Assault with intent to commit murder Felonious battery
© 2012 McGraw-Hill Higher Education. All rights reserved. 4
The Law
Homicide Nonfelonious homicides Felonious homicide
Murder Homicide
Justifiable homicide Excusable homicide
© 2012 McGraw-Hill Higher Education. All rights reserved. 5
The Medico-Legal Examination Brings in medical skills to bear on
injury and death investigations. Forensic pathologist
Studies how and why people die
© 2012 McGraw-Hill Higher Education. All rights reserved. 6
The Autopsy
The autopsy determines: Time and precise cause of death What type of weapon was employed? If multiple wounds were inflicted, which wound
was fatal? How long did the victim live after the injury? What position was the victim in at the time of
the assault? From what direction was the force applied? Is there any evidence of a struggle or self-
defense? Is there any evidence of rape or other sex-
related acts? Was the deceased under the influence of alcohol
or any type of drug?© 2012 McGraw-Hill Higher Education. All rights reserved. 7
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 (algor mortis) rigor mortis livor mortis (lividity) Cadaveric spasm (death grip) decomposition changes stomach contents
© 2012 McGraw-Hill Higher Education. All rights reserved. 8
Forensic Entomology
Study of the insects associated with a dead body which is used to determine the elapsed time since death.
© 2012 McGraw-Hill Higher Education. All rights reserved. 9
Forensic Entomology Body Area from Which to Collect
Insects
© 2012 McGraw-Hill Higher Education. All rights reserved. 10
Evidence From Wounds
Firearm Wounds 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
© 2012 McGraw-Hill Higher Education. All rights reserved. 11
Firearm Wounds
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
© 2012 McGraw-Hill Higher Education. All rights reserved. 12
Close and Distant Shots
Firearm Discharged at Close Range
© 2012 McGraw-Hill Higher Education. All rights reserved. 13
Close and Distant Shots
Firearm discharged from a distance
© 2012 McGraw-Hill Higher Education. All rights reserved. 14
Incised Wounds
Typically bleed a lot Are inflicted with knives or razors Are narrow at the edges and gaping
in the middle
© 2012 McGraw-Hill Higher Education. All rights reserved. 15
Puncture Wounds
Usually small and have little or no bleeding
Can be easily overlooked Cause death in the same way as stab
wounds
© 2012 McGraw-Hill Higher Education. All rights reserved. 16
Lacerations
Open, irregularly shaped wounds In an assault these wounds are
caused by clubs, pipes, pistols, or other such blunt objects
© 2012 McGraw-Hill Higher Education. All rights reserved. 17
Defense Wounds
Defense wound are suffered by victims attempting to protect themselves from an assault, often by a knife or club
© 2012 McGraw-Hill Higher Education. All rights reserved. 18
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
© 2012 McGraw-Hill Higher Education. All rights reserved. 19
Suicide
Reasons for suicide: Ill health Severe marital strife Recent emotionally damaging experience Financial difficulties Perceived humiliation Actual humiliation Remorse over loss of loved one Revenge
© 2012 McGraw-Hill Higher Education. All rights reserved. 20
Suicide
Methods Gunshot wounds Suicide by use of a shotgun Hanging Sleeping pills and other pharmaceuticals Drowning Cutting and piercing instruments Poisons Opiate-overdoses Gases Jumping from high places
© 2012 McGraw-Hill Higher Education. All rights reserved. 21
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
© 2012 McGraw-Hill Higher Education. All rights reserved. 22
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
© 2012 McGraw-Hill Higher Education. All rights reserved. 23
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
© 2012 McGraw-Hill Higher Education. All rights reserved. 24
Serial Murder 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.
© 2012 McGraw-Hill Higher Education. All rights reserved. 25
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.
© 2012 McGraw-Hill Higher Education. All rights reserved. 26
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.
© 2012 McGraw-Hill Higher Education. All rights reserved. 27