Forensics understanding death

Stare decisis

"to stand by decision" - previous legal decisions are to be followed

Describe the impact on time of death for each of the variables listed below. If you based your time of death estimates strictly on temperature loss to be 10 hours before the discovery of the body, would you reduce your 10hour estimate or increase your 10hour estimate if the body had been:Suffering from an illness before death

(increase time if they had a fever)

Describe the impact on time of death for each of the variables listed below. If you based your time of death estimates strictly on temperature loss to be 10 hours before the discovery of the body, would you reduce your 10hour estimate or increase your 10hour estimate if the body had been:Submerged in a lake

(probably reduce the time because most lakes are much cooler than body temperature)

Describe the impact on time of death for each of the variables listed below. If you based your time of death estimates strictly on temperature loss to be 10 hours before the discovery of the body, would you reduce your 10hour estimate or increase your 10hour estimate if the body had been:Exposed to windy conditions

(reduce time)

Describe the impact on time of death for each of the variables listed below. If you based your time of death estimates strictly on temperature loss to be 10 hours before the discovery of the body, would you reduce your 10hour estimate or increase your 10hour estimate if the body had been:Naked

(reduce time)

What is livor mortis and what does it normally look like?

Means "death color". Begins two hours after death occurs.More than 8 hours after death - color will remain.Temperature has an effect.Cooler temp - occurs slower.Warmer temp - occurs faster.Can tell you what position a body was in the first 8 hours after death.Blood pooled at face, chest - body face down.Blood pooled at back, buttocks, back of head - body face up. Can also tell if the body was moved.Dual lividity (pooling of blood).Occurs if person left in killed position at least 2 hours and then moved before lividity is permanent.

What is mechanism of death?

Mechanism of death is the specific change in the body that brought about the cessation of life (i.e. gunshot wound caused too much blood loss causing death)

Is the time of death more than 12 hours or less than 12 hours?total loss of 10.6°C

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Is the time of death more than 12 hours or less than 12 hours?total loss of 11.7°C

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Is the time of death more than 12 hours or less than 12 hours?total loss of 17.2°C

More

How does the appearance of the eye change after death?

A cloudy layer forms over the cornea after 2 hrs if eye is open

What effect does age, temperature and moisture have on the rate of decomposition?

Age:Young decompose faster than elderly. Size of body:Overweight people decompose faster than smaller people.Temperature:Naked bodies decompose faster than clothed bodies. Higher temps preserve corpses,Lower temps prevent bacterial growth, slow decomposition. Environment:Bodies decompose more quickly in air (oxygen rich). More slowly in water, or buried

The body felt cold to the touch. The thermometer gave a reading of 21.1°C (70°F) for the body temperature. No rigor mortis was evident, but livor mortis had set in with blood pooling along the back. There was no noticeable increase in bloating or bacterial activity in the digestive system and no putrefaction. The man had been dead for more than 48 hours. How is that possible?

Algor mortis- 26.8 hrs. Livor mortis + 8hr. 0-4 days based on decomp. He could have been refrigerated after livor mortis set in

Factors that affect when rigor mortis sets in and how long it lasts

Ambient temp: cooler the body, slower the onset; warmer the body, faster the onset. Person's weight:Body fat stores extra oxygen, will slow down onset. Type of clothing:Presence of clothing speeds onset. Naked bodies slow onset.Level of physical activity shortly before death.Exercise or struggling will increase onset rate.Sun exposure.Direct sunlight makes body warmer:increases onset rate.

What are four things that can affect the rate that a body cools after death?

Ambient temperature Weight of the body Type of clothing, or lack of it General health of person at time of death Level of physical activity at time of death Sun exposure

When do insects begin to inhabit the body?

Black putrefaction stage

When does the skin turn black?

Black putrefaction stage

The body dries out and smells of cheese

Butyric fermentation

A man was shot in the head, which led to exsanguination and brain death. What is the cause, mechanism and manner of death?

Cause- GSW to the head. Manner- homicide/murder.Mechanism- bleeding out/ brain death

A woman smoked since she was 19 and died at the age of 65 of lung cancer, which caused her to go into respiratory failure. What is the cause, mechanism and manner of death?

Cause: Cancer. proximate cause: smoking. Manner: natural. Mechanism: respiratory failure

What is the definition of death?

Cessation of life. Irreversible cessation of blood and circulation, Cessation of all brain activity. It is not one single event, it is a combination of a progression of events

What are the two major orders of insects that are used in forensic investigation?

Diptera (Flies) and Coleoptera beetles

T/F As the body decomposes the eye hardens

F

T/F Bodies decompose slower in air and slower in water or if buried.

F

T/F temperatures speed up bacterial growth and increase decomposition

F

Whorl

Fingerprint pattern with at least two deltas and a core

What must be considered when determining time of death?

Health of the individual, age, weight, ambient temperature- look at algor mortis, livor mortis and rigor mortis.

A woman died with her eyes open and on her back from carbon monoxide poisoning. What would her eyes look like after death? Where would livor mortis be seen and what would it look like?

Her color would be cherry red due to the carbon monoxide poisoning. Her eyes would likely have a film covering the cornea, and livor mortis would be seen on her shoulders, buttocks, and heels of her feet.

A dead body of an elderly gentleman was discovered in an abandoned building. Blowfly pupae were found on the body. A missing person's report was filed for an elderly gentleman who had wandered away from home just two days before. The body found was similar in age, height, and weight to the missing person. Could this possibly be the same person as the person described in the missing person's report? Explain your answer.

It is possible although unlikely due to the fact that blowfly pupae were already found on the body. Pupae generally set in around 18-24 days after death. Possible if there were factors present that increased the rate of decomp drastically

Is the time of death more than 12 hours or less than 12 hours?total loss of 4.4°C

Less

Is the time of death more than 12 hours or less than 12 hours?total loss of 7.9°C

Less

A man died lying on his right side of natural causes. He was found about 14 to 20 hours after death. Where would livor mortis be seen and what would it look like?

Livor mortis would be permanent at the point. It would be purple/red in color and found on the entire right side of his body.

A body found outside in the winter has a temperature of 91.6°F. Has the body been dead a longer or shorter time than in problem 1? Explain your answer.

Shorter. The cold weather will increase the rate at which the body cools.

When do enzymes begin to break down the intestines and organs?

Stage one Initial decay

T/F Higher temperatures dry out corpses preserving them

T

T/F Moist environments speed up decomposition

T

What is manner of death?

The category of death, homicide, suicide, accidental, natural, undetermined

Probative

ability of evidence to prove something that is material to a crime.

The speed of decomposition is dependent upon what factors?

age , size of body, temperature, environemnt, and clothing.

Plea bargaining

agreement in which a defendant pleads guilty to a lesser charge and the prosecutor in return drops more serious charges to avoid time for a trial

Arthropods

animals characterized by jointed legs, segmented body and a hard exoskeleton. They must molt in order to grow

Crime scene

any place where evidence may be located and gathered to help explain events

Drugs

any substance that alters the mind and body

Analgesic

any substance which relieves pain

Evidence

anything that tends to establish or disprove a fact.

ABO

basic classification system for blood types based upon the reaction of antibodies and antigens

Suicide

When a person kills themselves on purpose

Would clothing on the body have made a difference in determining the actual time of death? Why or why not?

Yes, the clothing will act as an insulator reducing heat loss.

Instar

a developmental stage of arthropods generally referring to changes in the size of the larvae

Grand jury

a group of people sworn to inquire into a crime

Preliminary hearing

a hearing before a magistrate or a judge to determine whether a person charged with a crime should be held for trial

Misdemeanor

a minor crime, less than a felony, usually punished with a fine or confinement other than in a prison

Expert witness

a person who is a specialist in a particular field of forensic investigation. They may be required to stand trial and explain the facts of the data, not their opinion.

Booking

a police procedure following arrest that records basic information about the suspect, a photo, and fingerprints

Blood factors

a specific combination of antigens, enzymes and proteins in the blood

Rigor mortis

a stiffness in the muscles that occurs shortly after death

Cannabis

a tall, annual hemp plant native to central asia from which marijuana is harvested

Chain of custody

a written record of all people who have had possession of an item of evidence

Circumstantial evidence

evidence based on suggestion rather than personal knowledge or observation

Latent print

fingerprint made by the deposit of perspiration or body oils; not visible until processed

Loop

fingerprint pattern with one or more ridges entering from one side, curving, then going out on the same side entered

Visible print

fingerprints that can be see with the naked eye due to a substance that such as blood, paint, ink etc.

Plasma

fluid portion of blood

Glastier equation

formula used for determining the approximate time period since death based on body temp

Antiserum

human or animal serum containing antibodies that are specific for one or more antigens

Fingerprint

imprint made by the ridge patterns on the tip of the finger

Core

in a fingerprint, an area found near the center of all loop and whorl patterns

Pathology

investigation of sudden, unexplained, or violent death

What is cause of death?

is the reason for the death (i.e. gunshot wound to the head). Proximate cause of death refers to an underlying cause of death as opposed to the final cause. -Example: radiation → cancer= radiation exposure is the proximate cause of death.

Serology

laboratory study of body fluids

Civil law

law that deals with non criminal suits brought or protect or preserve a civil or private matter

Statutory law

legislative acts declaring, commanding or prohibiting something

Class evidence

material that can be associated only with a group of items that share properties or characteristics.

Individual evidence

material that can be related to a single source

Controlled drugs

material whose possession is controlled by law

Bail

money put up to guarantee that the defendant will appear in court as directed.

Hemoglobin

oxygen carrier that gives red blood cells their color

Locard exchange principle

perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence.

Autolysis

process by which a biological cell self destructs

Species succession

progression of emerging insects found on a body after death

Indirect evidence

providing only a basis for inference about a fact

When does fluid begin to exit orifices of the body?

putrefaction through black putrefaction. At the end of black putrefaction the body is almost completely dry

Erythrocytes

red blood cells

Criminal law

regulation and enforcement of rights, setting the acceptable limits of conduct in society.

Material

relevant and significant such as material evidence.

Miranda rights

rights guaranteed by the constitution that police must tell arrestees about

Felony

serious crime such as a murder punishable by more than one year of imprisonment

Molt

shedding of an insect's outer exoskeleton

Probable cause

situation in which a reasonable and prudent person viewing the available information would conclude that a crime has been committed and that the suspect committed it.

When does bloat begin?

stage 2 putrefaction

Physical evidence

tangible items that tend to prove some material fact

Presumptive test

test that presumes the presence of the questioned substance

Hearsay

testimony given by a witness who relates not what he or she heard, saw, or knows personally, but what others have said

Confirmatory test

tests that specifically identify one substance

Common law

the body of law made up of judicial opinions and precedents

What is algor mortis?

the chill of death. Body heat falls after death About 1.5 degrees per hour immediately after death. Slowing to less than 1.0 degree per hour after about 12 hours. Heat loss is affected by the ambient temperature. Corpse temperature is measured by a thermometer inserted into the liver. Time of death is expressed as a range of time. Factors affecting heat loss:Cooler environment - loses heat faster.More body fat, clothing - loses heat slower

Algor mortis

the cooling of the body temp after death

Homicide

the death of one person by another person

Arraignment

the first act in a criminal proceeding where the defendant is brought before the court to hear charges and enter a plea

Arch

the least common and simplest fingerprint pattern. Arches that have no delta or core. All ridge enter one side and exit the other

Taxonomy

the science of classifying organisms

Dactyloscopy

the study of fingerprints

Entomology

the study of insects

Postmortem interval

time elapsed since a person has died

Indict

to formally accuse a person of a crime

Metamorphosis

transformation from an immature form to an adult form in two or more distinct stages.

Delta

triangular area found in all loops and whorl patterns

Testimonial evidence

what is said in court by a competent witness

Nolo contendere

when a defendant neither admits nor denies committing a crime but accepts the punishment as though he or she were guilty

Leukocytes

white blood cells

Name the 5 stages of body decomposition and be able to give a general explanation of what happens in each stage.

1. Initial Decay - 0-3 days. Within two days after death: Initial Decay.Cell autolysis begins.purplish staining occurs from blood decomposition.Face becomes discolored. 2.Putrefaction - 4-10 days. blisters. Abdomen swells with carbon dioxide (released by bacteria living in the intestines). Within six to ten days: PutrefactionCorpse continues to bloat with CO2 as bacteria continue to feed on tissuesEventually, gas causes chest and abdominal cavities to burst and collapse. Fluids begin to leak from body openings as cell membranes rupture. Eyeballs and other tissues liquefy.Skin Sloughs off 3.Black Putrefaction - 10-20 days.Very strong odor..Parts of flesh appear black. Gases escape and corpse collapses 4.Butyric Fermentation - 20-50 days.Corpse is beginning to dry out. Most of flesh is gone 5.Dry Decay/ Skeletal Stage - 50 days or more

What is the approximate time of death if the body temperature was 75°F?

19.7hrs

A naked, male corpse was found at 8 a.m. on Tuesday, July 9. The air temperature was already 81°F. The body exhibited some stiffness in the face and eyelids and had a body temperature of 93.9°F. Livor mortis was not evident. Approximately how long ago did the man die?Justify your answer.

2-3 hrs. 3 hrs using algor mortis. Livor mortis did not set in yet which means it is less than 8 hrs and likely around 0-3 hrs. Rigor mortis starts around 2 hrs

Determine the approximate time of death using evidence from algor mortis. Show your work. Approximately how long has the victim been dead if his body temperature was 91.6°F?

4.53 Hrs

At noon, a female corpse was found partially submerged on the shore of a lake. The air temperature was 81°F and the water temperature was about 61°F. Rigor mortis was not evident, and the body's temperature was 60°F. Livor mortis showed a noticeable reddening on the victim's back that did not disappear when pressed. Bacterial activity was not significantly increased, and the lungs were filled with water. Approximately how long ago did the woman die?Justify your answer.

41.14 hours using algor. More than 8 hrs due to livor mortis. Likely in stage 1 decomp due to no increase in bacterial activity and lungs still have water. However water will slow down decomp.

Approximately how long has the victim been dead if his body temperature was 85.2°F?

8.8 hrs

What changes happen to the eye after death?

The eye begins to dry out and an opaque film covers the cornea

What is rigor mortis and how long does it normally last?

The stiffness of death. Without oxygen in the blood— Calcium accumulates in the muscles . Muscles stiffen. Starts in the head and expands throughout. After about 15 hours— Muscle fibers begin to dissolve and softening begins

Natural Death

caused by interruption and failure of body functions resulting from age or disease. The most common cause of death

Accidental Death

caused by unplanned events (car accident)

Modus operandi

characteristic method of operation of a criminal

Bifurcations

common minutiae in a fingerprint shaped like a two pronged fork

Ambient

concerning the surrounding area or env.

Carrion

decaying flesh of dead animals

Putrefaction

decomposition of animal proteins especially by anaerobic microorganisms.

Oviposition

depositing of eggs (oviposit= to lay eggs)

Color of Lividity

determined by skin pigmentation and any additional compounds which may be present within the blood (i.e. carbon monoxide, etc.).areas where the blood has settled will generally be dark blue or purple in color.Carbon monoxide poisoning à lividity can be cherry red in color. Exposure to nitratesà lividity dark, chocolate-like brown color.Death due to intense cold or the refrigeration of a recently deceased body will produce a bright pink lividity.can also be produced if the area of the body was covered by wet clothing.

Livor mortis

discoloration of the skin caused by pooling of blood after death

Designer drug

drugs synthesized with a particular pharmacological characteristics designed for abuse

The only remains are bone and some hair on remaining skin

dry decay or skeletal stage