INTRO TO FORENSIC SCIENCES
Forensic science is the study and application of science to matters of law. Some people refer to it as criminalistics, or the study of crime.
Forensics utilizes a fundamental principle, which is called the Locard method; Edmond Locard was a forensic investigator in the early 1900s, and he stated that:
"Whenever two objects come into contact, there is always a transfer of material. The methods of detection may not be sensitive enough to demonstrate this, or the decay rate may be so rapid that all evidence of transfer has vanished after a given time. Nonetheless, the transfer has taken place."
This is good for forensic scientists, but also means that they have to be very methodical in their work. Any contamination of evidence deems the evidence useless.
This is why chain of custody is so important. At all times, the evidence of a crime must be accounted for. There must be a chronological record of the evidence, from the time it was collected to its presentation in court. Cases that take many years to see court must be handled with the utmost care in order for the evidence not to be misplaced or contaminated, as this can get a whole case thrown out of court.
Forensic scientists use crime labs to help them examine evidence.
Evidence is anything in the crime scene that can:
Forensics utilizes a fundamental principle, which is called the Locard method; Edmond Locard was a forensic investigator in the early 1900s, and he stated that:
"Whenever two objects come into contact, there is always a transfer of material. The methods of detection may not be sensitive enough to demonstrate this, or the decay rate may be so rapid that all evidence of transfer has vanished after a given time. Nonetheless, the transfer has taken place."
This is good for forensic scientists, but also means that they have to be very methodical in their work. Any contamination of evidence deems the evidence useless.
This is why chain of custody is so important. At all times, the evidence of a crime must be accounted for. There must be a chronological record of the evidence, from the time it was collected to its presentation in court. Cases that take many years to see court must be handled with the utmost care in order for the evidence not to be misplaced or contaminated, as this can get a whole case thrown out of court.
Forensic scientists use crime labs to help them examine evidence.
Evidence is anything in the crime scene that can:
- Help understand what happened, or reconstruct an event
- Help determine who may have been in a crime scene
- Clear some people who might have been suspects
Evidence is used to prove someone's statements in a trial. It can be used to either prove or disprove someone's account of events.
There are many kinds of evidence and not all are the same.
Physical evidence is a material or an object; it can be as large as a building and as small as DNA. It is much more reliable than testimonial evidence. People's memories can be iffy; eyes can deceive depending on the circumstances, and sometimes the mind plays tricks. Then there is indirect evidence, also known as circumstantial evidence, which helps prove a fact or explain how something happened, but is not enough to convict someone of a crime.
Forensic sciences use labs with many different departments:
There are many kinds of evidence and not all are the same.
Physical evidence is a material or an object; it can be as large as a building and as small as DNA. It is much more reliable than testimonial evidence. People's memories can be iffy; eyes can deceive depending on the circumstances, and sometimes the mind plays tricks. Then there is indirect evidence, also known as circumstantial evidence, which helps prove a fact or explain how something happened, but is not enough to convict someone of a crime.
Forensic sciences use labs with many different departments:
- physical science (including chemistry, physics, geology)
- biology
- ballistics
- document examination
- photography
- toxicology
- fingerprints
They can also consult with other specialists depending on the situation, such as:
- Anthropology
- psychiatry
- odontology
- engineering
- computer technology
- pathology
- geology
- environment science
- entomology (the study of bugs and insects)
- palynology (the study of pollen and other microscopic biological particles)
- polygraphy
- voiceprint analysis
Let's take a closer look at fingerprints. We all have them, and they are all different!
FINGERPRINTING
Fingerprints are one of the most common physical evidences found in a crime scene.
Let's imagine this scenario:
A burglar approached a house from the backyard late one evening, knowing that the owners were not home. He tried to open the window with a crowbar many times while he stepped over the flowerbeds, but failed. Finally, he broke a windowpane, reached through the hole scraping his shirt on the broken glass, turned the latch and raised the window. There was putty holding the wondow together, and he didn't realize how soft it was as he touched it with his fingers. He climbed in through the windowsill and was promptly bitten on the leg by the silent but deadly good boy waiting in the darkness. He gave the good boy a big steak with a sleeping pill, knocking it unconscious in minutes, and went upstairs to steal some jewelry. He found some watches, some gold and even a new iPad. On his way back, feeling pretty good about his haul, he stopped by the kitchen and took a big bite of a block of cheddar cheese which was in the fridge. He left a note near the cheese, saying "Thanks for everything, sukkkkkkerz", unlatched the door and left into the night.
Let's imagine this scenario:
A burglar approached a house from the backyard late one evening, knowing that the owners were not home. He tried to open the window with a crowbar many times while he stepped over the flowerbeds, but failed. Finally, he broke a windowpane, reached through the hole scraping his shirt on the broken glass, turned the latch and raised the window. There was putty holding the wondow together, and he didn't realize how soft it was as he touched it with his fingers. He climbed in through the windowsill and was promptly bitten on the leg by the silent but deadly good boy waiting in the darkness. He gave the good boy a big steak with a sleeping pill, knocking it unconscious in minutes, and went upstairs to steal some jewelry. He found some watches, some gold and even a new iPad. On his way back, feeling pretty good about his haul, he stopped by the kitchen and took a big bite of a block of cheddar cheese which was in the fridge. He left a note near the cheese, saying "Thanks for everything, sukkkkkkerz", unlatched the door and left into the night.
What evidence could link the burglar to the crime scene?
Make a list.
Let's share!
Make a list.
Let's share!
Let's concentrate on the fingerprints for now.
What exactly is a fingerprint?
A fingerprint is an impression of the patterns of ridges on the last joint of a person's finger. These are the things that make fingerprints useful for indentification:
What exactly is a fingerprint?
A fingerprint is an impression of the patterns of ridges on the last joint of a person's finger. These are the things that make fingerprints useful for indentification:
- They have unique, characteristic ridges
- They are consistent over a person's lifetime
- There is a systematic classification used for fingerprints
Fingerprint Classification
Let's take a look at the sheets given to you. Try to classify the fingerprints based on their main shapes!
