Forensic Week 2

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Questions and Answers

What was the main reason the jury believed the maggot evidence over the eye-witnesses in the Peter Thomas case?

The witnesses provided conflicting statements.

The body showed no signs of decomposition.

The police had prior knowledge of the suspects.

The entomologist’s findings supported the maggot evidence. (correct)

What is the scientific name of the blowfly mentioned in the Peter Thomas case?

Calliphora erythrocephalus (correct)

Lucilia sericata

Musca domestica

Chrysomya megacephala

During what time frame was Danielle van Dam reported missing?

February 1st evening to February 3rd morning

February 2nd evening to February 3rd morning

February 1st evening to February 2nd morning (correct)

February 2nd morning to February 3rd morning

What assumption did the police make regarding the time of death in the Peter Thomas case?

The victim was dead for 6-8 weeks. Signup and view all the answers

How long did Prof. Keith Simpson estimate Peter Thomas had been dead?

At least nine or ten days, not more than twelve Signup and view all the answers

What is indicated if a body is found hanging with discolouration in the lower parts?

Liver mortis is present in the legs. Signup and view all the answers

Which statement is true if a body displays dark discolouration?

It may indicate a prolonged period after death. Signup and view all the answers

What is liver mortis?

The settling of blood in the lowest parts of the body. Signup and view all the answers

If a pig's body displays signs of liver mortis, what can be inferred?

Liver mortis is evident if the body is horizontal. Signup and view all the answers

When can darkly colored discolouration primarily be observed in a deceased body?

After several hours to days post-mortem. Signup and view all the answers

What is the primary cause of rigor mortis following death?

Lactic acid in muscle tissue Signup and view all the answers

How long after death does rigor mortis typically affect the entire body?

12 hours Signup and view all the answers

What is the term for the settling of blood post-mortem due to gravity?

Livor mortis Signup and view all the answers

During which time frame after death is livor mortis most apparent?

0-12 hours post-mortem Signup and view all the answers

How does the body color change due to livor mortis?

Discoloration occurs in the lower parts of the body Signup and view all the answers

Which of the following is not a factor affecting the timing of rigor mortis onset?

Decomposition stage Signup and view all the answers

What is the typical time frame for rigor mortis to fully resolve after its onset?

12-24 hours Signup and view all the answers

Which of the following statements about rigor mortis is incorrect?

It affects all muscles equally at the same time. Signup and view all the answers

What is a significant factor influencing the rate of decomposition after death?

Local environmental factors such as temperature Signup and view all the answers

Which statement correctly describes putrefaction?

It involves microorganisms breaking down tissue. Signup and view all the answers

What characteristic phenomenon occurs as microorganisms break down tissue after death?

Production of gases and characteristic smells Signup and view all the answers

What type of evidence is highlighted as important in determining factors surrounding a death?

Mobile phone records and CCTV footage Signup and view all the answers

Which of the following is NOT true regarding livor mortis?

It is influenced by the clothing style of the deceased. Signup and view all the answers

Which of the following options is true about the decomposition process?

Drugs can influence the rate of decomposition. Signup and view all the answers

How does temperature affect decomposition?

Higher temperatures accelerate decomposition. Signup and view all the answers

Which process involves the breakdown of tissues after death, leading to changes in the body?

Putrefaction Signup and view all the answers

Which forensic technique indicates the variability in fluorine and uranium content in bones?

Absorption of elements from groundwater Signup and view all the answers

What does an increased nitrogen content in fresh bone indicate?

The age of the bone decreases as nitrogen breaks down Signup and view all the answers

Which of the following statements about the likelihood of time of death determination is correct?

Weather and microclimates can significantly impact the accuracy of time of death estimates. Signup and view all the answers

What conclusion was drawn about Piltdown Man based on its composition?

The nitrogen and fluorine levels suggested it was not of the same age. Signup and view all the answers

Why is nitrogen content not reliable for determining the time of death in skeletal remains?

Nitrogen can fluctuate based on environmental conditions. Signup and view all the answers

What evidence was crucial in the conviction of Westerfield?

Medical examinations and forensics combined with physical evidence Signup and view all the answers

What did fluorescence analysis indicate about skeletal remains?

The remains were at least 100 years old. Signup and view all the answers

What significant factor may complicate the analysis of a body covered in soil?

Absorption of nitrogen and fluorine from soil Signup and view all the answers

Which of the following is NOT a characteristic of contemporary forensic assessments?

Using outdated methods from historical cases Signup and view all the answers

What is commonly used to measure very small concentrations of trace elements?

Parts per million Signup and view all the answers

What is the primary disadvantage of using chemical tests for detecting elements in samples?

They are not sensitive to small amounts. Signup and view all the answers

How many grams are in one kilogram?

1,000 grams Signup and view all the answers

What is one method to identify the elements present in an object?

Bulk composition analysis Signup and view all the answers

What prefix represents one trillionth of a gram?

Picogram Signup and view all the answers

What phenomenon occurs when white light passes through a prism?

Refraction Signup and view all the answers

What is a characteristic of trace impurities in materials?

Often present in negligible amounts Signup and view all the answers

Which metal is commonly used in bullets that indicates bulk composition?

Lead Signup and view all the answers

What is a primary method of elemental analysis mentioned in the content?

Flame photometry Signup and view all the answers

Which element is NOT mentioned in relation to soil and bone analysis?

Iron Signup and view all the answers

What combination of techniques is mentioned for analyzing samples?

SEM and EDX Signup and view all the answers

Which physical process was used to match the trace element profile of soil?

Elemental profiling Signup and view all the answers

What was the context involving the person who was trafficked to West Germany?

A human sacrifice Signup and view all the answers

What type of analysis involves using neutron activation?

NAA Signup and view all the answers

What is the role of absorption spectrometry in elemental analysis?

To quantify the concentration of elements Signup and view all the answers

Where were the soil samples from that were matched to the trace element profile?

Nigeria Signup and view all the answers

What phenomenon leads to the discovery of helium in the solar spectrum?

Black bands known as Fraunhofer lines Signup and view all the answers

What was the role of Ernest Rutherford in atomic theory?

He developed the planetary model of the atom Signup and view all the answers

What prevents atoms from collapsing due to electrostatic attraction?

Presence of strong nuclear forces Signup and view all the answers

How does spectroscopy relate to light and atoms?

Different frequencies of light can reveal atomic structure Signup and view all the answers

What is the primary effect of passing white light through a prism?

It separates light into constituent colors Signup and view all the answers

What does the term 'Fraunhofer lines' specifically refer to?

Absorption lines in the solar spectrum Signup and view all the answers

What conclusion did Norman Lockyer draw from his investigations?

Helium exists in the solar spectrum Signup and view all the answers

Which of the following best describes the 'planetary model' of the atom?

A dense nucleus with electrons orbiting like planets Signup and view all the answers

What might affect the chemical composition of bones in a population?

Presence of various metals in the diet Signup and view all the answers

Which trace elements are mentioned as significant in indicating geographical origin?

Strontium, Copper, and Lead Signup and view all the answers

In traditional societies, what is likely to influence the trace element composition in bones?

Locally grown and consumed foods Signup and view all the answers

What is a potential outcome if an individual consumes a diet rich in certain metals?

Increased presence of those metals in bone Signup and view all the answers

What does the relative abundance of trace elements in bone indicate?

The geographical origin of the individual Signup and view all the answers

What is a primary advantage of using Atomic Absorption Spectrometry?

It provides rapid analysis. Signup and view all the answers

Which of the following accurately describes the principle behind Atomic Absorption Spectrometry?

It measures the loss of intensity related to the amount of the atom of interest. Signup and view all the answers

What is a common disadvantage associated with Atomic Absorption Spectroscopy?

It cannot measure multiple elements at once. Signup and view all the answers

What does EDX stand for in the context of X-ray analysis?

Energy Dispersive X-ray Fluorescence Signup and view all the answers

In Atomic Absorption Spectrometry, what kind of light is used in the detection process?

Light from a hollow cathode lamp at specific frequencies. Signup and view all the answers

What happens to the sample before it can be analyzed by Atomic Absorption Spectrometry?

It needs to be dissolved in acid to form a solute. Signup and view all the answers

Which component is crucial for the element separation in Atomic Absorption Spectrometry?

A monochromator. Signup and view all the answers

What is one key feature of non-destructive analysis in EDX?

It examines core electrons without altering the sample. Signup and view all the answers

What occurs when a higher energy electron drops to fill a vacancy created by ejecting a core electron?

A characteristic X-ray is emitted Signup and view all the answers

What differentiates Scanning Electron Microscopy (SEM) from traditional light microscopy?

SEM utilizes a beam of electrons instead of light Signup and view all the answers

What is the primary purpose of the electron gun in a Scanning Electron Microscope?

To fire a beam of electrons at the sample Signup and view all the answers

What technique combines SEM and EDX to enhance imaging capabilities?

SEM-EDX Signup and view all the answers

How does the intensity of emitted X-rays relate to elements detected in energy dispersive X-ray spectroscopy (EDX)?

It is correlated to the number of elements present Signup and view all the answers

What initiates the ejection of a core electron in the electron microscopy process?

The collision of an electron with the atom Signup and view all the answers

What is the diameter of a particle referred to as gunshot residue?

About 5 μm Signup and view all the answers

What typically occurs as the electron beam from SEM interacts with the sample?

Electrons bounce off and generate signals Signup and view all the answers

Study Notes

### Rigor Mortis

Lactic acid builds up in the muscles after death
This causes stiffening of the muscles
The stiffening starts in the smaller muscles (e.g., jaw) and progresses to larger muscles (e.g., legs)
Rigor Mortis typically lasts up to 36 hours after death
Timings are guidelines and other variables can affect the rate of rigor mortis

Livor Mortis

Settling of blood in the lower parts of the body due to gravity after death
This causes discolouration in the lower parts of the body
Livor Mortis develops between 0-12 hours after death
The position of the body can affect the discolouration
Livor Mortis can be used to determine if the body has been moved

Putrefaction

After death, microorganisms start to break down tissues
This produces gases and a characteristic smell
The rate of putrefaction is heavily influenced by factors such as temperature and drug use
Blowflies and their life cycle can be used to estimate the time of death

Forensic Entomology

The life cycle of blowflies can be used to estimate the time of death
maggots go through three instars (stages)
The age of the maggots can be used to determine when the body was first colonized by flies.

Peter Thomas Case

Peter Thomas' body was found in the woods in 1964
The body was covered in maggots
Forensic entomologist, Prof. Keith Simpson, estimated that Peter Thomas died around 9-12 days before his body was found
This evidence was used to convict the suspect, William Brittle

Danielle van Dam Case

Danielle van Dam was reported missing in 2002
Her body was found several weeks later in the mountains
Forensic entomologists estimated a range of possible times of death based on the stage of maggots found on the body
This evidence helped convict the suspect, David Westerfield

Time of Death from Skeletal Remains

Fluorescence analysis can be used to determine the age of skeletal remains.
- No fluorescence indicates remains are at least 100 years old.
Bone nitrogen content can be used to estimate the age of skeletal remains.
- Fresh bone is 4% nitrogen by weight
- The percentage of nitrogen decreases with age as proteins break down and nitrogen leaks into the soil
Bone fluorine and uranium content can be used to estimate the age of skeletal remains.
- Fresh bone contains 0% fluorine and uranium
- These percentages increase slowly with age due to absorption from groundwater.

Piltdown Man

Discovered in 1912-1915 in England
Claimed to be a human ancestor
Claimed age: 500,000 years
Later discovered to be a hoax
The bones were too young and had an unusual mix of modern and ancient features indicating the bones had been assembled fraudulently.

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Description

Explore the concepts of rigor mortis, livor mortis, and putrefaction in this forensic science quiz. Understand how these processes occur after death and their importance in forensic investigations. Test your knowledge on how environmental factors and entomology play a role in determining the time of death.