1. Forensic Science
An Introduction

2. What Is Forensics?
Forensic science is the application of science to law
Forensic scientists: are primarily concerned with examining contact trace material associated with crimes. This follows the principle that 'every contact leaves a trace' that will offer potential evidence to link a suspect with the scene of the crime, the victim or the weapon.

3. Typical Work Activities: The Forensic Lab
Chemistry - the examination of paint, chemicals, etc., including fire investigation and accident reconstruction;
Biology - DNA testing and the examination of minute contact traces, such as blood, hair, clothing fibres, etc.;
Drugs and toxicology - testing for restricted drugs, examining tissue specimens for poison detection, and the analysis of blood and urine samples for alcohol, for example in drink driving offences.

4. Forensic Sciences: The Big Umbrella
Forensic Chemists: the forensic chemist studies the molecular aspects of the crime scene.
Forensic Anthropologists - The forensic anthropologist examines the victims bones to determine a number of key facts.
Forensic Dentists/Odontologists - these experts serve an identification function by analyzing a corpse's teeth and previous dental records.
Forensic Linguists: the forensic linguist analyses either the spoken or written word..
Anthropologist: Information such as gender, age, looks, previous trauma, and disease can all be found.

5. Forensic Sciences: The Big Umbrella
Forensic Artist: the forensic artist provides an elaborate sketch of the offender.
Forensic Sculptors: like the forensic artist, the sculptor attempts to create an image of either an offender or a victim. The sculptor's goal is to create a three dimensional version of the image.
Ballistics Experts: ballistic experts focus on the functioning of firearms
Dactyloscopy: this is the scientific analysis of fingerprints.
Forensic Art: This process is undertaken via the information from an eyewitness. Many investigators now use computer programs to develop offender renditions.
Ballistics Experts: . Via microscopic analysis they can match up bullets with a particular weapon.
Forensic Chemists: They can match fibers, paint, and dyes to particular objects. They will identify relevant chemicals and particles.
Forensic dentist-. They also will analyze bite patterns so that they can identify who was eating a particular meal or even who bit somebody
Forensic serologist: The serologist is often involved in DNA fingerprinting (the identification of an individual based on body cells).

6. Forensic Sciences: The Big Umbrella
Forensic Entomologists: study insects and key information can be discovered such as the rate of body decay via insects can directly correlate to time of death.
Forensic Geologists: the forensic geologist can determine where a person or object has been by analyzing soil samples.
Forensic Serologist: the serologist studies blood and other bodily fluids for identification purposes.
Forensic geology: Soil can be found on a pair of shoes, tire treads, or a body. They can be matched up with common soil types to predict quite specifically where the object/person has been.
Forensic Linguists: They can identify whether a message was presented by the same individual, what the individuals underlying intent is, the individuals educational and cultural background, as well as the presence of pathology>
Forensic Photographer: They depict the scene from multiple angles, using multi-functional cameras, and through the consistent evaluation of size and distance

7. Forensic Sciences: The Big Umbrella
Forensic Pathologist: the forensic pathologist analyzes the remains of a body. They attempt to determine the cause and time of death via autopsy.
Forensic pathologists are trained to conduct comprehensive death investigations.
They require a medical degree, followed by several years advanced training in pathology.

8. Forensic Pathology: Investigation
Forensic Investigation
History
Physical Examination
Imaging Studies
Laboratory Studies
Forensic pathologists are trained to conduct comprehensive death investigations. Good forensic death investigations follow the traditional physician's approach of gathering history, performing physical examinations, and utilizing directed laboratory and imaging studies. All the information gained by these methods needs to be appropriately evaluated and considered in order to arrive at appropriate conclusions.

9. The Medical Examiner
A medical examiner is a medically qualified government officer whose duty is to investigate deaths and injuries that occur under unusual or suspicious circumstances, to perform post-mortem examinations & in some jurisdictions to initiate inquests
The medical examiner has jurisdiction over human remains, but does not have jurisdiction over scenes/places. By having jurisdiction over human remains, the medical examiner can access any scene/place where the human remains/body(s) are. When there is evidence of a death being unnatural and the body is still at the scene/place of injury and death or at the scene/place where the body (or remains) was first found dead (the body/human remains have not been transported from the scene to some other location), all reasonable efforts will be made to have a medical investigator and/or medical examiner-forensic pathologist respond to and examine the scene.

10. The Medical Examiner
It is not the authority, nor the responsibility of the Medical Examiner's Office to investigate or be involved with any 'medicolegal' issues
In cases of death that fall under the jurisdiction of the Medical Examiner, the body of the deceased must not be moved without Medical Examiner authorization
The differentiation between natural deaths and unnatural deaths is the appropriate focus of the Medical Examiner's Office.
The Medical Examiner may take charge of the remains of deceased individuals who died of natural causes when they are unidentified or unclaimed.
Conduct death investigation in the interest of the public as a whole, not to serve the self-interests of a particular individual or group. The mission is to seek out and speak the truth about a given death. It is recognized that the truth is not always very popular, but best serves the public as a whole.
The Medical Examiner's conclusions are intended to be shared with the public, individuals within the public, and other government agencies and public offices, but must be arrived at independently.
The Medical Examiner's conclusions are intended to be shared with the public.

11. The Crime Scene Investigation
The real crime scene investigators are highly trained police officers (Identification Officers)
They are trained in all aspects of crime scene analysis from photography, fingerprinting and DNA collection to blood spatter pattern analysis
The identification team collect the evidence, and submit it to the forensic scientists at the lab, who will then perform the analyses and submit reports to the Investigating Officers
are not civilians, as is so often portrayed on television,

12. The Crime Scene Investigation
The identification officer handles the crime scenes and is not responsible for other aspects of the investigation
Other police officers are involved in such things as interviewing suspects and following up leads
NO mistakes are allowed
Therefore, every Identification specialist can state in court, that they have NEVER mis-identified anyone

13. The Autopsy The Definition of “Autopsy”: ‘to see for one's self.’
It is not the same as the word “dissection”:
‘the process of disassembling and observing something to determine its internal structure and as an aid to discerning the functions and relationships of its components’
It involves:
observing the external and internal structures of the body to gain information about the individual's death

14. Anything and everything
The Autopsy
'What do you look for at autopsy?’
Anything and everything
Is there evidence of abnormal development?
Is there evidence of natural disease? Is there evidence of injury (physical, electrical, heat, cold, drug, chemical, radiation)?
Are there clues to the identity of the deceased?
Is physical evidence related to an unnatural event present?

15. The goals of the forensic autopsy are:
The Autopsy
The goals of the forensic autopsy are:
to discover information that cannot be obtained in other ways
to provide independent confirmation of what is known or
to provide a variety of means of documentation of findings
The performance of an autopsy is an important forensic tool to be applied to certain cases as needed, not an end point, and not a 'lab procedure' done on request.
The Medical Examiner has statutory authority to perform autopsies and post mortems.
The Medical Examiner has statutory authority to perform autopsies. Family permission is not required as it is in a hospital setting. This allows the Medical Examiner to function independently to serve the public. It is neither required nor proper to perform autopsies in all deaths. There are significant differences between hospital autopsies and forensic autopsies. The authority to perform autopsies is used judiciously where the examinations are needed to provide information critical to the investigation in the interest of the general public.

16. Real Life Forensic Science
Fact Vs. Fiction
Real Life Forensic Science

17. Who Invented Forensic Science?
No, not scientists “Necessity is the mother of invention” The use of fingerprints by the police to identify criminals was the first real application of science to law

18. Forensics: An Ancient Science?
The first crime claimed to have been solved by forensic science was:
The murder of Julius Caeser
In 44 B.C.
A physician named Antistius was called to study the corpse of Julius Caesar. Upon examination of the body, Antistius concluded who was responsible for the crime, and the guilty senators were sentenced to death. The physician made his fateful announcement in the Roman forum, giving forensic (forensic – from the Latin forensics, “belonging to the forum”) science its name.

19. Fingerprinting
Who were the first to use fingerprints in a legal system?
The Chinese used fingerprints to establish identity of documents & sculptures
When was the first fingerprint filing system devised?
In 1899, by Sir Edward Richard Henry, in his book “Classification and Uses of Finger Prints” – the system is still used by the FBI today
What system of identification was used before fingerprints?
Bertillonage system; measuring people’s bodies. The system used 11 measurements
What is the main system used by law enforcement for matching fingerprints today?
The Automated Fingerprint Identification System (AFIS)
The Chinese mainly used a thumbprint in place of a signature in on legal conveyances and criminal confessions. (in the 700’s)
In 1896, an English fingerprint scientist by the name of Sir Henry Edward, who was a pupil of Galton, created the 'ten print' system of classification, which became the most commonly used technique until the introduction of computers in the late 20th century. It was first implemented in India in 1897 and had its own unique way of classification. Edward divided the patterns in fingerprints into two groups known as value patterns, which contained whorls, and the no-value patterns, which contained loops and arches. from. A thumb on the right hand containing a whorl is valued with number 16, but the little finger on the left hand containing a whorl was only given a value of 1. Edward then grouped together values from certain fingers, forming a fraction-like code for each set of ten fingerprints. Altogether, Edward created 1024 individual codes, his pioneering work ensured that any set of prints could be filed using this code. His system of fingerprint filing worked very well in identifying criminals working under aliases.
Suspected criminals were fingerprinted and coded before being compared against known criminals stored under the same code, making it much faster searching for a match as investigators didn't have to search through the entire collection. This system did however, have some drawbacks, as a whole and complete set of ten fingerprints was required, making it difficult to identify single prints found at a crime scene. A single print identification system was later developed in the 1930's allowing the classification and filing of single prints from individual fingers.

20. Fingerprints Aren’t Foolproof
No two people can have identical fingerprints
Their patterns are so intricate and variable that it takes a well-trained eye to recognize a match. Computer technology has made this process a lot easier, but there is no completely foolproof method.
Even gloves leave prints
UV rays can reveal invisible prints
Getting a fingerprint off human skin is near impossible
Fingerprints Aren’t Foolproof
The computer systems used at present are able to scan fingerprints that have been found at a crime scene and automatically find and record the ridges, whorls, arches or loops contained within. This data is then compared by the computer with information that is similar in the database and finally produces a shortlist of matches in order of likeliness. The crime scene fingerprint is compared manually by investigators with the shortlist to identify any matches.
Just like fingerprints, no two glove prints are alike. Investigators can find the type and maybe even the size of glove worn.
Many things can be used to find latent prints, specifically lasers, powder, and UV rays. The FBI uses the Reflected Ultraviolet Imaging System (RUVIS) to reveal the latent prints.
A print on a corpse is the most useful as you know that the person who left the print touched the person, but getting a print off of a dead person is a very hard task. A fingerprint is made up of oils and so is the human body. This makes the latent print development very difficult.

21. Matching fingerprints is not an easy job
The comparison of fingerprints is a time consuming procedure and requires experience and great skill. Examiners look at the shape of the ridges and compare the points where the ridges start, end, join and split. The positions of short ridges, dots and any enclosed areas are also noted. Examiners also search for points of similarity between the fingerprint mark and the print to try and decide if the two patterns match.
At the crime scene: Visible prints are prints from of finger that has been coated in a colored substance like blood or dirt. Latent prints are invisible and must be developed. Plastic prints are prints impressed into a substance like wax or dust.
Loops are the most common type
Matching fingerprints is not an easy job

23. DNA Testing: The Star of the Show
DNA testing has cleared more than 242 convicted criminals of false charges
Deoxyribonucleic acid is a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms
It occurs as linear chromosomes; a set of chromosomes makes up the genome – and is divided into discrete units called genes
Genes are translated into proteins
It is present in ALL the cells (in the nucleus and mitochondria)
A minute amount is all that’s needed for analysis
How many? 46

24. Unique DNA? How much of your DNA sequence do you share? With mice: 92%
With chimpanzees: 98%
With humans: 99.9% (~100%)
You have 2 copies of every gene sequence, 1 from your mother, and one from your father. They are usually not identical. They code for “traits”; this determines your appearance & whether you carry any diseases.

25. DNA Analysis
Only about 1.5% of the human genome consists of protein-coding sequences, with >50% of human DNA consisting of non-coding repetitive sequences called 'short tandem repeats' (STR's)
The number of times the STRs repeat varies between individuals
This allows for identification.

26. Unidentifiable Victims
Often murder victims are discovered at advanced stages of decay.
This makes immediate identification of the body almost impossible.
Investigators have resorted to precise scientific methods to determine the identity of the skeletal remains.

27. Facial Reconstruction
Once the skin and flesh has rotted away from the skull of a corpse, their character and physical appearance disappear along with it.
Clay is used by sculptors and anthropologists to reconstruct a life like form of what the person looked like from the skeleton.
Thus helping identify the victim.

28. How Is This done? Depth of the skin must be measured.
Facial depth measurements are available for male and female, certain ages, racial groups, thin people and obese people
Concentrate on facial features
The eyes, mouth, ears, nose, chin, jaw and cheeks.
These give the face the most character.
Facial Features
The sculptor is then able to start work on the eyes, mouth, ears, nose, chin, jaw and cheeks, as these are the aspects of the face that give the most character, but are also the parts that perish most quickly as the body decays. Sculptors rely on certain rules during the reconstruction of a face, for example, the width of the nose is the same as the distance between the inner corner of the eyes and the corners of a person's mouth lie below the inner boarders of the iris. Ears are seen as being roughly the same length as the nose, though elderly people usually have longer ears. Once the facial features are complete, the sculptor makes a mould from the clay head using a plaster of Paris silicone rubber.

29. Sculptors must build the muscles around the skull.
The Face:
Sculptors must build the muscles around the skull.
They are able to approximate the size and insertions of the facial muscles by noting the shape and size of the bones of the face.
The sculptors then cover the clay muscles with a layer of clay skin which is smoothed over to resemble real skin.
Now, the reconstruction of the face involves the task of building the muscles around it. Sculptors must approximate the muscle structures by noting the shape and size of certain facial bones, as these will directly affect the shape of the muscles previously attached to them. Using their experience, the sculptors are able to build the face by shaping each of the muscles and then fixing each one in its place on the skull. The final step is to cover the clay muscles with a layer of clay skin, which is smoothed over so that it resembles real skin.  

30. Teeth Are Trustworthy
Dental records are responsible for identifying up to 93% of corpses.
Most reliable form of identification:
Every individual has a unique dental imprint
Sturdiness of bones means they are the best preserved human remains.
Identification for unrecognizable victims.
E.g.: Burning, Mutilation, Disfigurement of the body
21. You Can’t Lie Through Your Teeth
One of forensic science’s strangest pieces of incriminating evidence involved the crimes of Ted Bundy, one of history’s most infamous serial killers. His modus operandi was to violently bludgeon an innocent victim to a helpless state, and then strangle her to death. After his capture, he confessed to having killed over 30 women, although many believe that his actual body count was over 100.
Despite the blatant savagery of his crimes, Bundy was a highly intelligent man. He was able to skirt the law, and was not found guilty throughout 10 years of questioning. However, one piece of evidence proved beyond a shadow of a doubt that Bundy was indeed responsible for the heinous murders. He was found guilty based on dental matches to bite marks he left on the buttocks of one of his victims!

31. Bullets Aren’t Foolproof
Bullets are similar to fingerprints in the sense that the barrel of each gun has its own unique grooves and surfaces.
This creates a distinct imprint that acts as the “fingerprint” of the gun.
However, a bullet can be damaged upon impact, so finding a matching pattern becomes more difficult.
As the bullets shoot out of the gun, they fly through the barrel and are marked by that imprint. While this ballistics theory is sound, the process of actually finding a match for the gun and bullet has no strong statistical formula behind it.

32. Although authorities have been able to trace weapons from the bullets they fired (and from those who fired the weapons), the process itself is extremely meticulous and open for error.

33. What can bones tell us? Age: Gender Height Race Teeth Collar bone
Vertebral bodies (spine)
‘Ossification’
Gender
Skull & hip bones
Height
Reassembling the whole skeleton &
measuring the length of the significant bones
Race
Skull
One of the best indicators of race is cranial morphology, or skull shape.
The shape of the skull can also tell investigators a victim’s gender.
Hawaiians, for example, have a characteristic jaw that rocks back and forth if pushed (known as Rocker Jaw).
Males have slightly sloping foreheads, whereas females’ foreheads are vertical.
Details such as these help investigators analyze and identify remains.
Gender:
These are the ridges located above the eyes, the bone situated just below the ear and the occiput, the bone located at the lower back of the skull. The latter two bones are muscle attachment sites, all of which are more prominent in men, indicating greater strength. The difference in hips is very obvious, as a man's hip are narrower and a women's hips are wider, being built for child bearing. However there are smaller differences in other bones, which anthropologists rely on when there is no hip or skull bone.
Age:
Ossification occurs in 800 points of the body and is the best guide to revealing the age of a child's skeleton. An example of ossification occurs in the arms, where at the age of six, the two bone plates form at either end of the outer forearm (radius).At the 17 in males and 20 in females, the lower bone plate and the radius fuse together and soon after, the upper bone plate and radius fuse together. The bone in the body that finishes growing last is the collarbone, which ceases growth at 28 years. In the bones of the elderly, degeneration begins to occur. Anthropologists will look for tiny spikes that start to appear on the edges of the vertebrae, the wearing of teeth due to age and joints that show signs of arthritis. All of the bones in the body will deteriorate with age.

34. Piecing It All Together
The Crime Scene
The Autopsy
The Evidence
Identity
The Suspects
Crime Tools

35. Thank You
Questions?

36. Thank You Students: Jude Al Masoud Sara Al Munif Norah Al Saif
Roa Al Sajjan
Moneerah Al Gassim
Sarah Mahasin
Zeinah Al Halees
Lara Al Namlah
Third year Medical Students, King Saud University

37. Faculty Members Prof. Abdelmoty Mohamad Kamal Kabbash
Professor and head of Forensic Medicine & Toxicology Unit College of Medicine - King Saud University
Dr. Khaldoon Aljerian
MBBS, MHSc, FRCPC
Forensic Medicine Unit, Department of Community Medicine, College of Medicine - King Saud University
Dr. Theeb Alqahtani