History of Forensic Science and International Organisations - Term 1

Forensics Definition

• To bring before the forum or a court of law (in classical terms)

• Science applied to the law (in modern times)

How Science Came to Scotland Yard

Beginnings of Forensic Science ( 1788)

• Dr Samual Farr published “The Element of Medical Jurisprudence,” in Scotland; a.k.a. Forensic Medicine in today’s terms.

• (1790s) Prof. Andrew Duncan taught medical Jurisprudence at Edinburgh University

• (1807) The first British Chair of Medical Jurisprudence created by the Crown at Edinburgh University

• (1834) Dr Alfred Swain Taylor publishes “Elements of Judicial Jurisprudence”, laying the foundation of modern forensic medicine

• (1839) Glasgow University establishes a Chair of Medical Jurisprudence

• (1856) Alfred Taylor and a James Marsh perform the Marsh Test for arsenic in stomach content for the Parsons Cook case.

The Marsh Test

A chemical procedure developed to detect minute traces of arsenic in forensic toxicology.

• The suspected sample is mixed with arsenic-free zinc and sulfuric or hydrochloric acid

• Any arsenic in the sample reacts to form toxic arsine gas

• The gas is channeled through a glass tube and ignited, or passed over a heated surface, which causes the gas to decompose

Toxicology Definition

The science of detecting and identifying drugs, alcohol, poisons, and other chemicals in the body to help answer legal and criminal questions

Toxicology History

• Prof. Mathieu Orfila published a treatise on poisons and their effects on animals in 1814

Fingerprints History

Francis Galton published a book, “Fingerprints” (1892), and gave the first statistical proof of the uniqueness of fingerprints

William Herschel proved that fingerprints stayed the same throughout ones life

Edward Henry gave evidence to the Belper committee (1900) and then produced the “Henry System” which was made to classify fingerprints.

He then went on to establsih the Fingerpring Branch at Scotland Yard

(1905) The Deptford Murders

→ the first murder in which pingerprint recognition was used to find and convict the criminals

Identification (1879)

• Alphonse Bertillon developed Anthropometry as a means of identifying different people pre-fingerprints by measuring body parts

• The system relied on taking 11 specific physical body and head measurements (such as head length, head breadth, middle finger length, left foot length, and forearm/cubit length) under the assumption that bone structure stops changing after adulthood and remains unique to each individual.

• Measurements, facial descriptions, eye color, scars, and tattoos were recorded on cross-indexed cardboard files that could be sorted and retrieved

Ballistics

Goddard developed the science of identifying fired bullets and empty cartridge cases, known as forensic ballistics using comparison microscopes.

Goddard proved that no two revolvers are made exactly alike — that every weapon makes characteristic marks on a bullet and a cartridge shell, and that they are the same every time that gun is fired.

The 2 significant cases in which this was used was:

• The Saint Valentines Day Massacre (Fred (Killer) Burke)

• Nicola Sacco and Bartolomeo Vanzetti robbery-murder case in Massachusetts

Serology - Leon Lattes

• (1915) Lattes developed a means of grouping dried bloodstains by using saline solution to wet the staines then using normal grouping techniques

• They were grouped using blood cell antigens in the blood and the blood plasma : A, B, AB and O

• Before the advent of DNA profiling, they relied on a serological intelligence database known as the “Blood Index”

Beyond ABO Grouping

• To narrow down the suspect group, forensic scientists tested blood and bodily fluids

• Polymorphic Enzymes : variations found in specific enzymes found in red blood cells E.g. PGM, AK and EAP

• Secretor Status : 80% of people are “secretors” so they secrete ABO blood group antigens into other bodily fluids such as saliva, semen and vaginal fluids (critical for sexual assault cases).

Operational Mechanics

The Blood Index Served 3 primary functions :

• Scene Linking (serial offending) → if an identical, relatively rare serological profile was recovered from multiple crime scenes, the police was adivsed that a single serial offender was likely possible

• Suspect Elimination → proving innocence; blood markers are inherited and unchanging, so if a suspect’s enzyme profile did not perfectly match a crimes scene stain, they were definitively excluded from the investigation

• Target Profiling → if a suspect was arrested for an offence, their blood profile could be cross-referenced against the Blood Index to see if they matched biological evidence from outstanding, unsolved cases.

Limitations of The Blood Index

• Provided class evidence rather than individual identification so it could put a suspect in a specific sub-group of the population, but never 100% prove that a specific person left the stain

• Enzymes like PGM degrade quickly when exposed to heat, light or bacteria, meaning old or poorly preserved crime scene staines often yielded incomplete profiles.

Questioned Documents

Albert S. Osbourne developed the fundamental principles of document examination/handwriting analysis.

His work was used famously in the Lindbergh Kidnapping Case (1935)

→ Osborn and his team testified on behalf of the prosecution

→ He compared the handwriting of the suspect with that of the handwriting found on the ransom note

Scientific Crime Scene Examination

Hans Gross, an Austrian criminologist, helped establish modern criminal investigation by:

• Promoting the scientific and systematic investigation of crime scenes.

• Emphasising the importance of physical evidence and careful observation.

• Encouraging the use of scientific methods and specialist knowledge to solve crimes.

• Publishing Criminal Investigation in 1893, a pioneering work that helped develop criminalistics as a discipline.

Locard’ Principle

Edmund Locard

“When one surface comes into contact with another, there is a transfer of material from one surface to another and vice-versa”

• Brought about the idea of trace evidence at a crime scene.