Insects and Death - Winston Churchill Memorial Trusts · Insects and Death – Dr Andrew J. Hart 6...

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Studying forensic entomology in the USA and Canada

by

Dr Andrew John Hart BSc PhD FRES Fellow 2005

Forensic Scientist

Forensic Science Service Ltd.

A report for the Winston Churchill Memorial Trust

July to September 2005

Acknowledgements

First of all, I would like to thank the Winston Churchill Memorial Trust for giving me the

opportunity of a lifetime to study forensic entomology in the USA and Canada, and the

Forensic Science Service Ltd. for allowing me to take advantage of this. Secondly, I

extend my thanks to my hosts in the USA and Canada whose generosity was

overwhelming. They were Dr Jeff Tomberlin, Dr Jim Olson, Dr Mariana Griggs, Detective

Bill Pepsis and Kellie Lander from Texas; Dr Jeff Wells and Christine Picard from West

Virginia; Dr Richard Jantz, Dr Lee Jantz, Dr Murray Marks, Dr Bill Bass, Dr Steven

Symes and Dr Anne Kroman from Tennessee, Dr Neal Haskell and Joel Haskell from

Indiana; Dr Gail Anderson from Vancouver; and Dr M. Lee Goff from Hawaii. Last, but

not least, I would like to thank Dr Martin Hall and Amoret Brandt from the Natural History

Museum for their help and advice.

Blowfly larvae

Insects and Death – Dr Andrew J. Hart 3

Aim The aim of my Winston Churchill Fellowship was to learn more about forensic

entomology by meeting leading experts in the USA and Canada. I aimed to achieve this

by establishing contacts with American and Canadian forensic entomologists, travelling

to research institutes and universities, work shadowing, completing a research project

and giving presentations. I would potentially apply the knowledge and experience

gained to further develop forensic entomology within the UK.

General introduction Introduction I saw the Winston Churchill Fellowships advertised in the newsletter of the Forensic

Science Society, and immediately thought that this could be an ideal opportunity to

combine my interest in entomology (the study of insects) and forensic science. I decided

upon an initial itinerary and began to make contacts with forensic entomologists in the

USA and Canada. I had selected this part of the world as it had the highest

concentration of forensic entomologists and there was an interesting range of

opportunities available. I completed the necessary forms, obtained permission from my

employer and waited nervously for a response. I knew competition would be tough, but

fortunately I was short listed and passed the panel interview. I was very pleased to have

reached this stage and I was now free to plan my itinerary, book flights and

accommodation and hire cars. Prior planning and organisation was the key to a

successful fellowship and I was pleased about the way my arrangements began to fall

into place. There was a fair amount of flying involved and I was on a tight schedule, as it

was all based on the availability of the forensic entomologists I was going to meet. Once

the flights had been booked, contacts made and visits arranged I knew that this

Fellowship was going to offer me the chance to gain a real insight into forensic

entomology.

My background I am a forensic scientist working at the Forensic Science Service Ltd., specializing in the

examination of biological evidence, which includes the identification of body fluid staining

and the interpretation of DNA profiling results. I produce statements for court and I am

trained as an expert witness. Prior to this, I trained and worked as an applied


entomologist for over eight years. I studied for a PhD at

the University of Birmingham on the effects of

temperature on the growth and development of hoverflies

in the UK. I continued my research at the University

during a post-doctoral research fellowship on the

biological control of insect pests, before becoming a

Research Leader in applied entomology at Horticulture

Research International. I had twelve scientific papers

published on my scientific research during my academic

career. I am working towards combining my training as

an entomologist with my role as a forensic scientist in the form of forensic entomology.

What is forensic entomology? Forensic entomology is the interpretation of insect evidence to help in criminal

investigations. It involves the study of the biology, behaviour and distribution of insects

at a crime scene, which can give information on when, where and how a crime was

committed. The key aspect of forensic entomology is the estimation of minimum time

since death or post-mortem interval (PMI). However, it can also provide clues with

regard to the possible movement of a corpse, in cases of abuse or neglect, food

infestations and toxicological studies. Insects can also form potential sources of human

DNA after feeding on a corpse, which can provide additional information in a murder

investigation.

Blowflies (bluebottles and greenbottles) are the

key group of forensically important insects for a

number of reasons. They are the most commonly

found insects on dead bodies and are usually the

first insects to arrive at a corpse, whereupon they

begin to feed and lay eggs. Blowfly larvae

(maggots) are the critical stage used in estimating

the minimum time of death.

It is important to have an understanding of the life

cycle of blowflies when studying the role of these Blowfly larvae


insects in the decomposition of a dead body. Adult flies are attracted to the openings in

the head (nose, mouth, eyes), anus, genitals and any wounds that may be present on

the body, where they lay their eggs in masses around these sites. The eggs hatch out

into first stage (instar) larvae and pass through two more stages, before leaving the body

as post-feeding or ‘wandering’ larvae. The larvae move away from the body, often

forming long trails, and subsequently bury into the soil. They change into puparia in the

ground and adult flies form within the puparial cases. The adult flies break out of their

cases, crawl up through the soil and are then free to begin feeding, mating and laying

eggs again.

With an in depth knowledge of insect,

particularly blowfly, biology, behaviour and

distribution it is then possible to estimate

the minimum time of death of a person. It is

useful to describe decomposition of the

body at the crime scene and to note any

insect activity. After this, it is important to

collect insect specimens following the

correct protocol so that the insects can then

be analysed at the laboratory. The insects

need to be identified and their life stage

noted. Any blowfly larvae collected are aged by using their size and estimates of

temperatures that they may have been exposed to before reaching that stage. The age

of maggot gives an estimate of the period of insect activity on the body or the minimum

time since death. Death may have occurred before the insect activity commenced as

the insects may have been prevented access to the body until later, for instance if the

body was in a sealed container.

Collections of blowflies

It is important to gain hands on experience of forensic entomology including insect

sampling techniques at a crime scene, insect identification, time of death calculations,

casework and research. The Winston Churchill Fellowship allowed me to have this

unparalleled opportunity.


The FellowshipThe Fellowship Itinerary - Summer 2005

Florida - North American Forensic Entomology Association (20th to 22nd July)

Texas - Dr Jeff Tomberlin, Texas A&M University (25th to 29th July)

West Virginia - Dr Jeff Wells, West Virginia University (1st to 5th August)

Tennessee - Anthropological Research Facility (8th to 26th August)

Indiana - Dr Neal Haskell, St Joseph’s College (29th August to 2nd September)

Vancouver - Dr Gail Anderson, Simon Fraser University (5th to 9th September)

Hawaii - Dr M. Lee Goff, Chaminade University (12th to 16th September)

Map showing route across the USA and Canada


North American Forensic Entomology Association Conference, Orlando, Florida

I attended the North American Forensic Entomology

Association (NAFEA) conference at Disney World,

Orlando, Florida. It gave me the opportunity to make

initial contact with a large number of experts as well as

meeting some of the forensic entomologists that I was

going to be seeing later in the trip. There were a series

of presentations on forensic entomology together with

topical discussions. I became a member of the NAFEA and there is also the potential for

me to become an accredited forensic entomologist with appropriate experience.

Dr Jeff Tomberlin, Texas A & M University, Stephenville and College Station, Texas My next stop was Dallas, Texas, from where I travelled down

to Texas A & M University at Stephenville and College Station

to meet Dr Jeff Tomberlin. He is an assistant Professor of

entomology, President of the NAFEA and one of America’s up

and coming forensic entomologists. He carries out research

on forensic and animal health entomology while working on

cases alongside this. I was also introduced to two other

forensic entomologists during my visit, Dr Jim Olson and

Marianna Griggs.

Dr Jeff Tomberlin

Catching flies on a dead goat

Dr Tomberlin kindly provided me with a dead goat to study

during my stay in Texas. I made a photographic record of its

decomposition and collected insects from various sites of the

body and at different times of the day. I preserved and

pinned the insects that I had collected and identified a

number of them by using taxonomic keys. We discussed his

casework and he allowed me to study and make copies of

his substantial literature collection. Dr Olson showed me his

work on pig decomposition, discussed his casework and he


guided me through his mosquito research involving transmission of West Nile Virus. I

gave a presentation to students at the university on my entomology research and role as

a forensic scientist.

The generosity of Dr Tomberlin, his wife, colleagues and family was in true Texan style,

with the provision of huge steaks, ‘grill outs’ and strawberry pie. As well as learning a

great deal about forensic entomology, I also experienced some of the famed southern

hospitality during my stay.

On my last day in Texas, I travelled back to

Dallas to visit the Dallas Police Department and

Dallas County Forensic Institute, which my

Dallas friend, Kellie Lander, had kindly helped

to arrange for me. Detective William Pepsis,

lead trainer in the Crime Scene Investigation

(CSI) Unit took time to discuss the CSI training

programme and the role of the investigator at

crime scenes in Dallas, and how forensic

entomology would be part of this. I was given a

tour of the unit, including the DNA labs,

fingerprint section, gun department and blood

room. He introduced me to the Chief Medical Examiner, David Gabutz, who discussed

his role as a medical examiner while guiding me around the morgue and autopsy suites.

They have to contend with a huge number of unnatural deaths on an annual basis partly

due to the fact that Dallas has one of America’s highest murder rates. I was impressed

with the way they dealt with this.

Dr Jeff Wells, West Virginia University, Morgantown, West Virginia I flew from Dallas to Pittsburgh, where I was greeted by Dr

Jeff Wells, an Associate Professor of forensic science

based at West Virginia University in Morgantown, West

Virginia. Dr Wells is a leading expert in use of DNA

technology in relation to forensic entomology, using DNA

techniques to identify forensically important flies. The West Virginia University


techniques include the gathering of mitochondrial DNA sequence data followed by

phylogenetic analysis (construction of ‘family trees’ of flies). There is a real need for

such methods of identification as it can be difficult to identify immature flies using

traditional techniques, as the samples may be degraded or at early life stage such as the

egg or first instar larvae. It is also possible to identify whether or not there is human

DNA contained in the larval gut after they have been feeding on a body. This makes it

possible to tell whether or not a particular larva, which may have moved away from the

body, has been feeding on the corpse, and therefore it can be used in the estimation of

the minimum time of death. Also if a body has been moved, it is sometimes possible to

obtain an identity of person from human DNA extracted from any larvae that remain

behind at the crime scene having fallen from the body.

Dr Wells and his colleagues

instructed me in the identification of

flies and their larvae using both DNA

and traditional techniques. This

gave me hands on experience of

these methods and a valuable

insight into the advantages of the

application of modern techniques. I

spent part of my time in the

countryside of West Virginia with a

postgraduate student, Christine

Picard, in order to collect road kill,

as it acts as an attractant to carrion

feeding flies and other associated

insects. We collected the insects from the rotting corpses to identify and preserve them

as well as to add to Christine’s laboratory insect colonies.

Collected road kill

I am grateful to Dr Wells, his wife, colleagues, students and friends for making me very

welcome during my stay in West Virginia, and for giving me the opportunity to learn

some important techniques in the field of forensic entomology.


Anthropological Research Facility, University of Tennessee, Knoxville, Tennessee My next stop on the Fellowship was for a three week stay at Knoxville, Tennessee to

visit the Anthropological Research Facility (ARF) run by the Department of Anthropology

at the University of Tennessee. The ARF is also infamously known as the ‘Body Farm’,

as used by the crime author Patricia Cornwell as the title of one of her novels. Upon my

arrival, I was greeted by Dr Richard Jantz, a Professor of Anthropology and the director

of the ARF, Dr Lee Jantz, the coordinator of the body donation programme and Anne

Kroman, a postgraduate researcher. I was also introduced to Dr Murray Marks, an

Associate Professor of Anthropology and Dr Steven Symes, an Assistant Professor in

Anthropology and specialist in dismemberment cases. Once I had overcome my initial

trepidation, the next three weeks wor

Entrance to Anthropological Research Facility

king at the ARF proved to be an extremely

teresting and informative experience.

in


Professor Bill Bass, a pioneer of forensic

anthropology, founded the ARF in 1980 in order to

deepen the understanding of physical

anthropology, particularly in relation to time of

death estimations in forensic cases. I had the

pleasure of meeting Professor Bass during my

research at the ARF. It is a three-acre site situated

on a wooded hillside close to a hospital just outside

of Knoxville. Scientific research is carried out at the

facility into the decomposition of humans and the

establishment of time since death. The skeletons

are cleaned, sorted and added to the Department

of Anthropology’s collection for further study and

research. The advantage of this collection is that

the prior history of the individual is known, so the bone structure can be related to this for

research purposes and for when comparisons are made to unknown bones collected

from a crime scene. The ARF is also used for body recovery training courses for the

FBI.

Dr Bill Bass and Dr Andrew Hart

Approximately eighty to one hundred bodies are donated each year, primarily by their

owners and families, but also from medical schools, and occasionally unclaimed

homeless people or murder victims, if the bodies have not been claimed from the

morgue after six months have passed. The coordinator stressed that there was no way

to predict when they would receive a new donor; sometimes they may not have any for a

few weeks while at other times they may have a number donated within a few days. I

was fortunate enough to be able to

study two donor bodies during my

stay. The Facility collect donors within

a 250 mile radius of the site, otherwise

the donor’s family are required to

organize delivery to the hospital

morgue. From the morgue, they are

transported to the Facility, and are

generally placed on the ground still House and car used in crime scene scenarios


within their body bag. As most scientists at

the Facility are interested in studying the

bones, the cadavers can be left in situ for up

to a year until the flesh rots away. However,

for research purposes they can be placed

exposed in the open, clothed or naked and

also in various ‘crime scene’ scenarios, for

example in a car boot, indoors or buried. Impression of a body left in concrete

I was only the second entomologist from UK to have visited the ARF, after Amoret

Brandt of the Natural History Museum, London, and only the fifth entomologist in the

world. Therefore, it was a rare opportunity for me to be able carry out research there. I

designed a research project, in collaboration with the Natural History Museum, which

involved the study of insect activity in relation to the decomposition of dead bodies. I

basically monitored insect attraction, selection of oviposition (egg-laying) sites, larval

development, formation of maggot masses, larval migration and selection of pupation

sites.

I recorded ambient, rectal, oral and dorsal temperatures of the bodies using data loggers

and probes (see Fig.1). In addition, I monitored temperatures of the maggot masses

that formed using a non-invasive infra-red thermometer and sometimes temperatures

reached over forty five degrees centigrade. I created a photographic record of

decomposition of the two donor bodies,

taking pictures twice a day, every day, for

three weeks from the same angles each

time. At the same times of day, I

collected eggs, larvae, pupae and adult

insects that were present on and around

the body, resulting in the formation of a

substantial insect collection. I made a

written record of the insect activity and

state of decomposition, which included Net and kill jar for adult insects


the monitoring and measuring of the post-feeding migration of larvae away from the

body. Back in the laboratory, I reared some of the specimens that I had collected in

order to ease the identification of the insects.

F ig . 1 A m b ie n t , lo w e r b a c k , o r a l a n d r e c t a l t e m p e r a t u r e s o f f e m a le 5 4 - 0 5 a t t h e A n t h r o p o lo g ic a l R e s e a r c h F a c i l t y , A u g u s t 2 0 0 5

0

5

1 0

1 5

2 0

2 5

3 0

3 5

4 0

4 5

8 . 8 .0 5 9 . 8 . 0 5 1 0 . 8 .0 5 1 1 . 8 .0 5 1 2 . 8 .0 5 1 3 . 8 .0 5 1 4 . 8 .0 5 1 5 . 8 .0 5 1 6 . 8 .0 5

D a t e

Tem

pera

ture

(°C

)

).

A m b i e n tB a c kO r a lR e c t u m

Decomposition itself consists of a number of processes including the enzymatic

liquefaction of cells, bacterial decomposition of tissue, the drying of the skin and

remaining soft tissue, followed by skeletonisation. The rate at which this occurs

depends on environmental conditions, particularly temperature and humidity. The two

bodies I worked on demonstrated almost the whole process of decay, as the

temperature and humidity during August in Tennessee provided almost ideal conditions

for bacterial and insect activity. Therefore, I was able to observe almost the whole

sequence of events that occur in the decomposition of a dead body. The female donor

rapidly progressed from fresh to almost skeletonised in only nineteen days. There was


a large amount of insect activity, with thousands of larvae forming huge maggot masses

on the body.

Insect activity has a major role to play in

the decomposition of a human body; in

fact the human body can lose up to sixty

per cent of its mass in a week to maggot

feeding activity. Decomposition and

related insect activity forms a continuum

but has been divided into a number of

stages for ease of explanation. The fresh

stage includes the time when blowflies

are attracted to the body to begin feeding

and egg laying, especially around the

head, anus, genitals and open wounds. During the bloated stage a variety of changes

occur including putrefaction, the release of gases from the activity of anaerobic bacteria,

maggot feeding which helps to cause increases in the temperature of the body, the

attraction of many blowflies and the leakage of fluids from the body and ammonia from

the metabolic activity of larvae which makes the local soil alkaline in nature. The skin

breaks and the gases escape leading to deflation during the decay stage. Maggot

masses and beetles are also present in this stage, and larvae start leaving the body to

pupate in the soil. Most of the flesh has been removed before entering the post decay

stage, leaving skin, cartilage and bones, beetles are more common. Finally, in the

skeletal stage, all that remains of the body are bones and hair, with few or no carrion

insects present.

Inside the Anthropological Research Facility

Working conditions were fairly challenging as temperatures were regularly over thirty five

degrees centigrade in August with high humidity and hundreds of mosquitoes, but it was

a real opportunity to work in an area where few other people have. My study visit made

me fully appreciate the processes involved in decomposition and the vital role insects

played in this. It made me realise how important insects actually were and it was truly

fascinating to watch the speed at which they developed on the body. Seeing thousands

of maggots all migrating in one long trail from the body, having completed their feeding,

was an impressive sight. It was extremely useful to have had first-hand experience of

observing how insects have such an important role in decomposition. The data that I


have collected will prove invaluable once it has been analysed, and it will hopefully be

published as a scientific paper in collaboration with the Natural History Museum. There

is a real need for fundamental research such as this in forensic entomology.

Dr Neal Haskell, St Joseph’s College, Rensselaer, Indiana Dr Neal Haskell is a Professor of forensic science and

biology at St Joseph’s College and is America’s only

independent forensic entomologist, working on an

average of forty to fifty cases on an annual basis. He

has an impressive knowledge of the subject, having co-

authored a manual of forensic entomology, and is one of

the most experienced caseworkers. He also runs an

extensive research program using pigs as models of

human decomposition. Dr Haskell guided me through a

number of his live cases, and he allowed me to carry out

preliminary identification of the flies. We discussed in

detail a number of his high profile cases involving

forensic entomology and his subsequent court

appearances as an expert witness. It made for

fascinating and informative discussions. During the

week, I observed the decomposition and insect activity

on three pigs that Dr Haskell had generously provided

for me, from which I collected and identified carrion feeding insects. I also assisted in a

debate during one of his forensic science classes and helped in the teaching of an

outdoor crime scene class.

Dead pigs in Indiana

Dr Haskell, his family and students showed excellent hospitality towards me and made

me feel very much at home in Indiana. I learnt a great deal about forensic entomology

and its application to criminal investigations.

Dr Gail Anderson, Simon Fraser University, Vancouver, British Columbia Dr Gail Anderson is Canada’s leading forensic entomologist as well as being an

Associate Professor of forensic science and Associate Director of the undergraduate

forensic program at Simon Fraser University. Dr Anderson runs an extensive research


program including monitoring the

decomposition of submerged pigs in the ocean

and the effect of fire on insect evidence on

bodies. We discussed this research in depth,

and I viewed a number of videos showing the

research on underwater pigs and fire damaged

properties containing dead pigs. I learnt more

about the calculations used to estimate the

minimum time of death in live casework, which is an essential component of any case

involving forensic entomology. Dr Anderson introduced me to a wide range of her

colleagues, from anthropologists to criminologists, which gave me an insight to other

areas in forensic science. I had the opportunity to visit the British Columbia Institute of

Technology, which runs a forensic training program for police personnel. During the

week, I gave a presentation on ‘forensic science in the UK’ to the forensic students at

Simon Fraser University, as it was the start of their Autumn Term.

Simon Fraser University

Dr Gail Anderson generously spent time away from her academic role to give me an

insight into how forensic entomology is practiced in Canada, and also how it fitted into

the wider area of forensics in a University environment.

Dr M. Lee Goff, Chaminade University, Oahu, Hawaii Last but not least, I went on to meet Dr. M. Lee

Goff who is based at Chaminade University in

Honolulu, Oahu, Hawaii. Dr Goff is the chair of

the forensic program at the University, a

Professor of forensic entomology and one of the

worlds leading practitioners, with over twenty

years experience in the field. He has been

involved in hundreds of cases across the USA,

backed up by an extensive research based

background. He is the author of the book ‘A Fly

for the Prosecution’ as well as being a consultant for the popular fictional forensic

television programme ‘CSI’. While in Hawaii I observed pig decomposition and insect

Dr M. Lee Goff


activity and discussed his casework and research. I was also able to add to my now

substantial literature collection.

Dr Goff again demonstrated a willingness to help in my objective to learn

more about forensic entomology, and was generous to a fault in

extending me some Hawaiian hospitality on the last stop of my

Fellowship.

Conclusions

Outcomes and follow up On my return to the UK, I have been busy capitalising on the success of my Fellowship

both in terms of publicity and the benefits to my career in forensic science, although I still

have a great deal of work to do. I am aiming to analyse the insect samples that I have

brought back from the ARF and to identify the specimens. I shall also be producing a

display case with the best specimens, to be used as an educational tool and for

reference purposes. Once I have analysed the

samples and related this data to the recorded

temperatures and stage of decomposition, I shall

submit the results for publication in the scientific press.

I shall maintain links with the forensic entomologists

that I met during the Fellowship, with possible

collaborative research projects being undertaken in the

future. I have also been invited to return to the ARF to

carry on with my research.

Insect samples

One of the objectives of a Fellowship was to promote and publicise the Winston

Churchill Memorial Trust and its Fellowships. I believe that I have made substantial

progress with this, and it is still ongoing. I organised press releases in liaison with Lucy

Stokes, from the Communications Group at FSS Ltd. As a result of this, there was

extensive media interest in my trip, which led to articles in the Metro News, Police

Professional (which is distributed to 20,000 police officers), ‘Clued Up’ (an internal

publication at FSS Ltd.), Lab News, Rugby Advertiser, and Lawrence Sheriff School

newsletter. There were also seven pages on ITV Teletext about my Fellowship. I have


had interest from the Sunday Express, Birmingham News Team, BBC 1 drama

producers, Channel 4 documentary makers and the Wellcome Trust in conjunction with

Channel 5 (discussing the ‘CSI effect’).

As well as the media interest, I have been invited to give talks to a number of audiences

including pathologists at the national meeting of the Association of Clinical Pathologists

in Prague and to students and staff at Kings College London, London Metropolitan

University, Wolverhampton University and Southbank University amongst others. The

Forensic Science Society and researchers at Exeter University and the University of

Central Lancashire expressed an interest in my studies on forensic entomology. I

organised a display stand demonstrating the potential of forensic entomology at an open

day at FSS Ltd., which proved to be hugely popular amongst staff and their family and

friends. Staff from FSS Ltd., police officers and forensic science students have

approached me on an individual basis either in person or by email to talk about their

interest in forensic entomology and how impressed they were by my Fellowship.

Conclusion I have learnt a huge amount about forensic entomology, which really would not have

been possible by just reading books and papers. To have actually seen the insects in

action taught me so much more than that. I experienced many different ways of working

by visiting so many different forensic entomology practitioners, which was an excellent

opportunity for me.

I met the aim of my Fellowship, which was to study and learn more about forensic

entomology by meeting leading experts in the USA and Canada. I achieved this by

developing contacts with American and Canadian forensic entomologists at various

universities and research institutes, completing a research project and by giving

presentations. Forensic entomology is an under-exploited area of forensic science and I

am hoping to share my research and promote its wider use.

None of this would have been possible without the opportunity provided to me by the

Winston Churchill Memorial Trust and the support from my employer. It certainly was a

‘chance of a lifetime’ and has benefited me in more ways than I could ever have

imagined and I thoroughly recommend anyone to apply for one.

Insects and Death - Winston Churchill Memorial Trusts · Insects and Death – Dr Andrew J. Hart 6...

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