fORENSIC EXAM 14-18

hree Elements of Rape:

Carnal knowledge (the slightest penetration of the labia minora by the penis)

Force (use or violence, threat of violence or coercion)

Commission without consen

very 107 seconds, another American is sexually assaulted

ata from the National Women’s Study, a longitudinal telephone survey of a

national household probability sample of women at least 18 years of age, show

683,000 women forcibly raped each year and that 84% of rape victims did not

report the offense to the police

Fatalities occur in about 0.1% of all rape cases

single ejaculation can release 2.5 to 6 milliliters of seminal fluid.

Each milliliter can contain 100 million or more spermatozoa, the male

reproductive cell

Absence of trauma to a rape victim does not negate the validity of her claim of rape

CODIS enables federal, state, and local crime labs to exchange and compare DNA

profiles electronically, thereby linking crimes to each other and to convicted offenders

CODIS generates investigative leads in crimes where biological evidence is recovered

from the crime scene using two indexes: the forensic and offender indexes.

The Forensic Index contains DNA profiles from crime scene evidence.

The Offender Index contains DNA profiles of individuals convicted of sex

offenses (and other violent crimes) with many states now expanding legislation to

include other felonies

Mitochondrial DNA:

mtDNA is used when the biological evidence is either small in quantity or

degraded.

mtDNA is inherited solely from the mother.

Individuals can have more than one type of mtDNA (heteroplasmy). This does

not invalidate the use of mtDNA for forensic analysis

1 in 5 women and 1 in 40 men in the United States are victims of rape or attempted rape

during their lifetime

rom 2016 through 2018 the number of rape/sexual assault victimizations in the United

States increased 146%

ost intimate partner homicides are committed with firearms.

n 2005, there were 3,582 fatal unintentional drownings in the United States, averaging

ten deaths per day

Of these, two are children aged 14 or younger.

rom 2005 – 2015: There have been approximately 10 unintentional drowning

deaths per day

Males: In 2005, males were four times more likely than females to die from

unintentional drownings in the United States.1

• Children: In 2005, of all children 1 to 4 years old who died, almost 30% died from

drowning.

Drowning was the leading cause of injury death for children 1 to 4 years of age.

Within the 5 years of 2013–2017, over 21,000 people died due to drowning in the United

States. In 2017 alone, there were 4508 fatal drownings with the majority of those being

unintentional (82%). Approximately three-quarters of people who die from drowning are

male and about one in six people who die from drowning are children aged 14 and younger

Drowning: Defined as death caused by submersion in a liquid.

• Can occur in an ocean or in only 6 inches of water.

• The mechanism of death in an acute drowning is irreversible cerebral anoxia.

• The most important physiological consequence of drowning is asphyxia.

• The volume of water inhaled can range from relatively small to quite large.

• “Dry drowning” – Lungs are not heavy, boggy, and edematous. A fatal cerebral hypoxia

is alleged to be caused by laryngeal spasm. Said to be responsible for 10 to 15% of all

drownings. A physical plug consisting of foam, thick mucous and froth forms and water

never enters the lungs. This is a hypothesis and not a proven fact.

The main factors associated with drowning risk are as follows:

Lack of swimming ability

Alcohol and or drug abuse

Lack of barriers to prevent unsupervised water access

Lack of close supervision while swimming (drownings can occur even in the presence of

lifeguards)

Failure to wear life jackets when boating

Seizure disorders

Long QT syndrome and other medical event

The time in which cerebral anoxia becomes irreversible is dependent upon:

o Age of the individual

o Temperature of the water

➢ In warm water, this time is between 3 and 10 minutes.

➢ In icy cold water, with the submersion of children, this time can be as long as 66

minutes following drowning. (Has resulted in successful resuscitation with intact

neurological outcome.)

Near Drowning” - Refers to a submersion victim who arrives at an emergency facility and

survives for 24 hours

Autopsy Findings:

➢ Diagnosis is based on circumstances of the death and a variety of nonspecific anatomical

findings.

➢ Chemical tests are generally nonspecific and unreliable.

➢ Drowning is a diagnosis of exclusion – must have a complete autopsy and

toxicological workup.

➢ “Washer-woman" changes to skin of hands.

➢ White or hemorrhagic edema fluid is present in the nostrils, mouth and airway

Drowning can be homicidal

Carbon monoxide poisoning is a year-round threat.

It is a colorless, odorless, tasteless, non-irritating gas

• Most common sources of CO in deaths are

– fires

– automobile exhaust

– defective heaters

– incomplete combustion of burning products

Carbon monoxide is produced whenever organic materials are burned with an inadequate supply

of oxygen necessary to produce complete combustion

Approx. 2700 deaths caused by CO annually in the U.S. (excluding fire deaths)

2000 = Suicides

700 = Accidents

Most suicides involve inhalation of automobile exhaust.

CO produces tissue hypoxia by competing with oxygen for binding sites on the oxygen-

carrying hemeproteins (hemoglobin, myoglobin, etc.)

• The affinity of CO for hemeproteins varies from 30 to 500 times as much as oxygen

– for hemoglobin it is 250 to 300 time greater

• Carbon monoxide displaces oxygen atom

t is believed that CO has a toxic effect at the cellular level by impairing mitochondrial

respiration

he percent saturation of CO is defined as the percentage of hemoglobin combined

with CO in the form of carboxyhemoglobin (COHb

Very low concentrations of CO in the atmosphere can produce very high

carboxyhemoglobin levels

Smokers generally have “normal” levels of carboxyhemoglobin at 5-6%, can

commonly reach 10% and can even exceed 15%

% Carboxyhemoglobin: Symptoms and Medical Consequences

• 10% No symptoms. Heavy smokers can have as much as 10 to 15%

carboxyhemoglobin

60%+ Death

After fires, the second most common source of CO in fatalities is inhalation of the exhaust

fumes of vehicles. Most of these deaths are suicides.

• CO diverted into a vehicle or other small area can significantly raise the temperature of

this space. This can account for postmortem skin slippage in some cases.

• The carboxyhemoglobin levels of persons who die from CO poisoning can vary greatly,

depending upon:

• Source of the CO

• Circumstances surrounding the death

• Health of the individua