The Body of Evidence

The English King, Richard III, was killed at the Battle of Bosworth on 22nd August 1485.  Contemporary accounts reveal that he was fighting heroically while pressed on all sides by his enemies, the armed forces of the rebel Henry Tudor (later Henry VII).  Famously (and possibly erroneously) depicted by Shakespeare as a murderous, unscrupulous monster, Richard III was the last English king to be killed in battle.  So why am I writing about a long-dead monarch in a forensics blog?  Keep reading to find out! 

 

An archaeological team from the University of Leicester, in association with Leicester City Council and the Richard III Society, has been excavating the site of a mediaeval Franciscan friary in Leicester called Grey Friars. 

On September 12th 2012, while excavating the choir of Grey Friars church, which is believed to be the burial place of Richard III, archaeologists discovered a grave containing human remains.

Could the remains be Richard III?  We shan’t know the answer, or even whether the question can be answered, until early in 2013.  But forensic science is playing a key part in the identification process.

Here is the link to the most recent article on the discovery, which outlines the scientific techniques being employed.  

The Science of the Search for Richard III

 

I imagine that the ‘ancient DNA’ technique being used is Mitochondrial DNA (mtDNA) analysis. Mitochondria (sing. Mitochondrion) are found in the cytoplasm of cells i.e. outside the nucleus.  They are one of the most important ‘organelles’ of a cell, since they are the site of the chemical reactions of respiration, whereby energy is generated for the needs of the cell.  A typical cell contains about a thousand mitochondria.

Old bones, badly decomposed or charred bodies are often poor sources of nuclear DNA, used in standard DNA profiling.  This is because the nuclear DNA becomes degraded, chemically modified or contaminated, and it is not possible to obtain a profile.  Mitochondrial DNA, although not immune to degradation, is better protected within the cell than nuclear DNA.  Its extreme abundance means there is a much greater chance of some of it surviving for longer.  

Human mtDNA is a circular molecule of DNA.  Most of it does not vary between individuals and therefore cannot be used as a forensic identification tool.  However, in a region of the molecule called the ‘D Loop’ or ‘Control Region’, variation does exist in DNA base sequences between unrelated individuals, which is of forensic value.    

I don’t plan to go into the minutiae of the technique here, but I will mention an important point about the inheritance of mtDNA. 

All brothers and sisters in a family will share the same mtDNA as their mother, but not their father.  They will also share the same mtDNA as their mother’s siblings and their grandmother.  This is because an individual inherits their mtDNA only from their mother.

As a consequence, mtDNA analysis cannot provide a unique identification because many individuals can have the same mtDNA base sequences.  Even between unrelated individuals, mtDNA analysis is not as discriminating as standard DNA profiling. The process itself is also not as straightforward as standard DNA profiling.  But it can generate data when standard DNA profiling fails, and this is the technique's undoubted advantage.

I’m very interested to discover that a (male) potential descendant of Richard III’s sister through the female line has been found, so that his mtDNA base sequences can be compared with the base sequences that, hopefully, will be obtained from the mtDNA of the remains.

It would be great if the scientific team are able to find sufficient evidence from their research to suggest that the remains are Richard III.  Follow me on Twitter @forensicswrite to find out.

 



A Question of Expertise

How many Forensic Scientists does it take to change a light bulb?  Answer: Two. One to screw it in and one to check for fingerprints.  Okay, it’s a pretty lame joke, but I’m using it to demonstrate that, in the real world, forensic scientists stick to their own area of expertise.

Each member of the forensic teams of CSI demonstrates proficiency in a wide range of disciplines.  There is seemingly no specialism beyond the scope of their expertise.  The use of such a multi-skilled cast of characters is partly a cost issue, of course.  However, engaging the viewer by re-visiting the characters week by week is a good way of developing loyalty to the show. 

In reality, of course, there is a clear demarcation between examinations carried out at the crime scene and those performed in the forensics laboratory.  Within the laboratory itself, a DNA specialist, for example, would not examine documents or perform toxicological analysis.  Each scientist keeps within their own discipline.

Crime scene investigators ‘read’ and reconstruct the events that took place immediately before, during and after the crime was committed.  They ascertain the type and location of the evidence and collect and package it correctly.  They document and photograph their actions throughout.  They also produce reports on their scene visits, which will form the basis of their expert testimony in court.

In the forensics laboratory, the scientists process the pieces of evidence collected by the scene investigator, whilst documenting all their actions in detail.  They too will produce reports on the results of their analyses, and may be summoned to appear in court as expert witnesses.

So you can see that the two roles are not interchangeable.  However, there is nothing to stop a scene investigator with a suitable science degree from moving into the forensics laboratory and training to become an expert in a single discipline.  They will already have a ‘feel’ for forensics, which can be a big advantage during the early stages of their new career.

Ultimately, it is up to you to decide what sort of forensics expert you want to create.  You could even invent an ‘expert’ who received his certificate of competence to practice from a diploma mill online! 

I’ll finish by wishing all my US readers a Happy Thanksgiving.  I hope you have a wonderful time.



Making an Impression

It is 1979.  A man walks into a bank, covers his face with a balaclava and hands the only cashier on duty a note and a carrier bag.  The note reads:  'I HAVE A GUN.  GIVE ME THE MONEY OR I WILL SHOOT YOU'.  The terrified cashier thrusts some notes into the carrier bag and hands it to the man.  He runs off, just as the cashier manages to activate the alarm..  In his haste to escape, he forgets to ask for the return of his demand note.  Two days later, he answers a knock at the door and discovers two police officers, who have come to arrest him for armed robbery.  He is so surprised that he confesses on the spot.

 

A police officer told me a version of these events many years ago.  The story may be apocryphal, but it serves to illustrate the major impact of a piece of newly operational forensic equipment, not only in solving cases of armed robbery, but also terrorism, murder, fraud and corruption, for example.  The existence of  ESDA (ElectroStatic Detection Apparatus) was not widely known amongst the criminal fraternity in its earliest days, but its use in  a widely reported case of police corruption ensured that its existence eventually became public knowledge.

 

So what is ESDA and what does it do?

 

According to Foster and Freeman, its manufacturers, ESDA is 'the leading technology for detecting indented writing on questioned documents'.  When you write on the top sheet of a pad of paper, the writing will leave indented impressions in the sheets underneath.  In my armed robbery story, indented impressions of the offender's address were found on the demand note.  Just how many sheets will bear impressions depends on the writing implement, the degree of pen pressure and the type of paper.  Writing made with a ballpoint pen with reasonably firm pressure on good quality paper may leave indented impressions on up to six underlying sheets.  On the majority of these underlying sheets, the impressions are not visible on the paper surface.  However, ESDA is such a sensitive technique, that it may be possible to visualise the impressions on all six sheets.

 

The equipment is very easy to operate.  Here is a video of a police officer developing indented impressions in documents from a murder case. 

 

 

 

 

ESDA works by creating an invisible electrostatic image of the indented writing onto the surface of a plastic film.  The impressions are visualised by pouring a mixture of glass beads and charge sensitive toner (like you find in photocopiers) over the surface, until the image is developed.  A permanent record of the image can be made by covering the surface with a sheet of adhesive transparent plastic. Known as an ESDA 'lift', the resultant transparency consists of the plastic film bearing the visualised indented impressions covered by the adhesive plastic.  The lift is trimmed to size and can be used to overlay writing which is suspected of having produced the impressions or simply read for information purposes.  If the impressions are of particularly good quality, they can form the basis of a forensic handwriting comparison with a suspect's writing.

 

A variety of information can be obtained from indented impressions.  If a page has been torn out of a diary, ESDA may be able to detect what was removed by examining the pages on either side.  In a murder case, where the victim knew her attacker, the victim had made a note in her diary that she would be meeting her attacker on this particular day.  Whilst checking that there was nothing to connect him with the crime, the murderer discovered the victim's diary.  He tore out the offending page and threw it away.  An ESDA examination of the pertinent pages of the victim's diary revealed the attacker's name.

 

A man committed suicide and left a bitter note for his wife.  She has destroyed the note because she feels she drove her husband to take his own life and cannot face his family.  Eventually, she tells the police that there was a note and it had been written on the pad by the telephone.  An ESDA examination of the top sheet of the pad would show exactly why her husband committed suicide and why she felt so guilty.

 

A suspect in a case of money laundering passed four handwritten receipts to the police, which, he stated, accounted for four large payments made into his business bank account.  The receipts covered a four month period between June and September 2007 and were dated at monthly intervals.  The police suspected that the receipts were false and had been created purely to legitimise the transactions.  Were the dates on the receipts genuine?

 

By using ESDA, it was discovered that there were indented impressions of the writing from the receipt dated in September 2007 on the receipts dated in August, July and June 2007.  There were also impressions of the August receipt on the July and June receipts and impressions of the July receipt on the June receipt.  This is clearly impossible if the receipts are dated correctly.  Undoubtedly, all the receipts had been written at one sitting and their dates were not genuine.

 

I'm sure you could think of many more examples where ESDA would be invaluable in helping to solve crimes.

 

A big bonus of the ESDA technique is that the document containing the impressions is not damaged in any way,  Furthermore, provided that the document has not been treated with fingerprint reagents, the technique still works after many years, and could, therefore, be of value in cold cases.

 

So when your characters decide to send a handwritten anonymous letter or plan an armed robbery on paper, they should take care what they leave behind!