Week 5 - Forensic archaeology, anthropology and ecology

Forensic archaeology

Applies archaeological methods to locate, excavate, and analyze human remains and other evidence at crime scenes

Main tasks of a forensic archaeologist

• Evidence searches

• Evidence recovery

• Evidence recording

• Scene interpretation

What is involved in forensic archaeology?

• Search and location

• Practicals of grave digging

• Principles of geophysics

• Surveying

• Recording and planning

• Skills and knowledge relating to excavation, layering and disturbance of soil, methods of geophysical survey

What does a mound mean?

That the body buried underneath it is relatively fresh and recent as when a body decomposes it released fluids and gasses that temporarily push the ground upwards, creating the mound, however when the gasses escape and the body has decomposed fully, the mound will drop and flatten

The Tollund Man

Was found centuries after he was buried as his body was naturally preserved in a peat bog (due to chemicals in the bog), he was found with a cord around his neck and so was thought to be sacrificed, were able to extract a porridge-like substance from his stomach, he was thought to have been poor as cremation was standard in Denmark at the time

What does referencing mean?

Using grids to map out the site and pinpointing where an object was found in relation to that site

Forensic anthropology

The analysis of skeletonized remains in the context of a criminal investigation, can determine whether body is human, what age it is, gender, ancestry, individual features, form of death, dismemberment, time since death

What can skeletons indicate?

• Age

• Sex - pelvis wider in women

• Handedness - bones in dominant hand slightly thicker through repetitive use (in older people)

• Damage/medical work

• Oesteobiography

• Distinct and individual damage (fractures, cause of death, what happened after death)

• High or low wealth based on how well-preserved their teeth are

• Insights into their death

• Evidence that fire was involved

• Wear and tear - what kind of work they were involved in

Probable age and age of remains

The older the bones are, the more likely it will be to approximate age. Length and development of bones, especially long bones and finger bones, are indicative of childhood/adulthood

Identification

Using forensic odontology to compare skeleton’s teeth with dental records - teeth can indicate the age of a person at death as teeth wear and tear in unique ways, and are expected to have worn in certain ways at certain ages, e.g. if teeth are well-worn, person was probably older

Trial and error

• Estimates from skeletons have degrees of error

• Gender is most reliable estimate, stature and age estimates less so

• Statistic/estimates can be based on old collections of skeletons - due to diet changes, technology and work changes, the nature of skeletons may now differ and lead to error

Facial reconstruction

A largely artistic process with a limited and dubious quantitative and scientific basis, the accuracy of which has been overstated, but it may be a method of generating media and public interest

Example of inaccurate facial reconstruction

Facial reconstruction of Ean Coutts looked nothing like him, however someone was able to identify him from his reconstruction, so even though it was inaccurate, it was still helpful (esp. in the early stages of an investigation)

What is forensic ecology?

The examination of animals, plants, fungi, bacteria, geology, soils and bodies of water

Forensic ecology contributes to…

• Estimation of post-mortem interval

• Demonstration of pathway and events around incidents

• Linkage of people to places

• Location of crime or evidence

• Difference between kill sites and find sites

• Establishment of cause of death

• Challenging/confirming evidence/statements

Soil

• Variable - huge range of soils in different areas across the world, this evidence can be used to place someone

• Readily transferable - onto individual (clothes, soles of feet, underneath fingernails), or objects (cars, footwear, tools), depending on how wet/dry it is

• Gives indication about environment body was in and what weather it was

• May retain impressions - such as a body being dragged

• Can indicate how bodies react with the environment - e.g. the grass on top of a buried body will grow faster than the surrounding grass

Layering of soils

Can be important. As soil gets deeper, the weight of the soil compacts it so it is lighter at the top and easier to manipulate, and darker as it gets deeper and becomes more impacted and less easy to manipulate

Palynology

The study of microscopic entities that are scattered away from its source

Pollen and spores

• Are diverse in shape and surface orientation

• Resistant to chemical, biological and mechanical degregations (can last for centuries)

• Widespread and easily and unnoticeable transferred

• Are essentially the DNA of the tree, which can provide indication about the origin and journey of something

• Human body can absorb them - walk through them, inhale them, consume them, may sit on our skin

Spores are produced by…

Fungi and seedless plants

Pollen is produced by…

Seed bearing plants

What clues can the way a plant recovers give us?

• Stepping on plants can break stems, snap branches - can show a journey

• Dragging a body might break branches, snap twigs and stems, and new shoots will come through a while later that indicate that something has happened in that area

Case of Joanne Nelson (2005)

• Body missing for 39 days

• Paul Dyson (boyfriend) admits murder but can’t remember where body was buried, apart from near a gate and beside some trees

• Patricia Wiltshire found 3 unusual plants in a sample

• From the basic geographical clues given by Dyson and the identification of the 3 plants growing in close proximity, the body is located

Mass graves in Srebrenica, (1995)

• 7000 men executed when Srebrenica falls to Bosnian Serb forces upon the break up of Yugoslavia

• They were buried in mass graves, but 3 months later the culprits attempt to make it look like local skirmishes rather than planned executions

• Forensic scientist compared soil from 5 primary sites and 19 secondary sites

• Samples taken from clothing and human remains

• The movement of bodies is proven through soils, pollen, hay and cartridges, showing that the majority of victims did not die in the locality in which they were found

What was one of the first recorded applications of excavation? (Litherland et al., 2012)

1943 in the Katyn Forest, where Germans exhumed thousands of Polish victims with the aim of establishing Soviet culpability for their deaths

What is best practice for archeologists? (Litherland et al., 2012)

For two archeologists to provide mutual support and assistance at a scene. They should provide advice to the police team and the reasons for any decisions made should be fully documented

What may a forensic archeologists be required to advise on at a crime scene? (Litherland et al., 2012)

• Search, location, excavation and recording of clandestine graves

• Search for other buried items including firearms and drugs

• Investigation of suspicious area of sunken and disturbed ground

• Exhumation for cold case reviews

• Contextual dating of bones

How can aerial photography help? (Litherland et al., 2012)

• Changes caused by disturbances of the ground such as burials can persist for thousands of years and in the right conditions are visible on aerial images

• Recent aerial photos can be compared to older images to assess what changes there have been to the landscape

• Can be used to survey large areas of land where field search may be impractical

How long has aerial photography been used by forensic archeologists for? (Litherland et al., 2012)

Over a century (Barber, 2011)

How can thermal imagery be used? (Litherland et al., 2012)

• To detect heat given off by decomposing bodies

• More useful in locating recent burials or decomposing surface remains

What is LIDAR? (Litherland et al., 2012)

An air-mounted form of radar-based ground survey which provides rapid and detailed survey of large areas and is capable of reading the ground through tree cover

What can geophysical survey be used for? (Litherland et al., 2012)

To indicate areas of disturbance beneath the ground which are not visible on the surface

What is resistivity? (Litherland et al., 2012)

A form of geophysical survey, measures resistance to an electrical current passed between sets of electrodes in the ground. Works well over long-standing graves but doesn’t work well is target is several metres deep or in very dry or wet environments

What is magnetic survey? (Litherland et al., 2012)

Form of geophysical survey where anomalies in the earth’s magnetic field are measured to uncover mixing of the top and subsoil, silting up of the grave, ferrous metal or burning. Doesn’t work well when there is background noise from overhead power cables

What is GPR? (Litherland et al., 2012)

Ground penetrating radar, a form of geophysical survey where radiowaves are emitted into the ground and bounced back from subsurface features to give a 3D profile. Can detect voids in walls and floors, less affected by background noise, works well over sand, gravel, limestone, ice etc. but doesn’t work well in clay soils

What is topography? (Litherland et al., 2012)

The physical features and shape of the earth’s surface

What does burying human remains do to the soil? (Litherland et al., 2012)

Alters the profile of the soil and creates a dynamic micro-environment, may cause the ground to become wetter or more loosely compacted and free draining, will set in motion changes in overlying vegetation

What changes to topography might there be if there are buried remains? (Litherland et al., 2012)

• Humps, bumps and hollows which do not fit in with the natural landscape

• The ground will sink as the body decomposes and defined edges may be seen

• Soil overlying a grave may be cracked

• Deposits of soil may be present around the grave

What changes to vegetation might there be if there are buried remains? (Litherland et al., 2012)

• Organic content of the soil may increase which will be toxic and cause overlying vegetation to look brown, stunted and unhealthy

• As body decomposes, nutrients are produced at beneficial levels so plants will grow better and appear more lush, green and taller than those surrounding them

• Different plants that prefer organic rich soil or disturbed ground (such as nettles) may take over

What are topography and vegetation changes dependent on? (Litherland et al., 2012)

• Time of year

• Type of environment

• Depth of burial

• Any coverings around the body or burial

What must archeologists do when recovering artefacts? (Litherland et al., 2012)

• Record all actions at the scene (individuals present, departure and arrival times etc.)

• Ensure artefact is investigated using most appropriate archeological technique

• Advise on samples to be collected

• Understand scene protocols, entry and exit routes, contamination avoidance

Why might archeologists evacuate a test pit? (Litherland et al., 2012)

To understand the geology of the area (what is natural is not natural). Usually done 5m away from the potential target