Unit 4
Career Paths in Forensic Science - Part 2
Fingerprinting
Analysis
Follow along with pages
17-24 in your text.
For more than 150
years, fingerprints have been collected and analyzed o help solve crimes.
Fingerprints can be found on almost any solid surface, including the human
body!
There are three
categories which fingerprints get classified under:
1. Plastic Prints
Figure 1 Microsoft Bing
Often three-dimensional
and found on soft surfaces (soap, wax, fresh caulk, wet paint, etc.).
2. Patent Prints
Figure 2 Microsoft
Bing
Visible prints are
found on hard surfaces.
Patent prints occur
when blood, dirt, ink, paint, or another substance on a thumb and fingers
transferrers to a surface that is porous (paper
or wood) or nonporous (glass, metal,
or plastic).
3. Latent Prints
Figure 3 iStock
Invisible prints were
found on a hard surface.
Fingerprint Collection
When collecting patent fingerprints, high-resolution photography is used. As a
reference, a forensic measurement scale is included in the image for reference.
On the contrary, dusting a surface with
fingerprint powder is one way to help discover fingerprints when discovering
latent prints. As a result, the fingerprint analyst takes a picture of the
fingerprint, uses a clear adhesive tape to lift the print to the surface, and
places the fingerprint on a lift card to be used as evidence. One downside to
using fingerprint powder is that it can damage evidence and limit the
techniques used to discover latent prints. Fingerprint analysts have to use
laser and LED devices to look for fingerprints. These lasers and LED devices
emit a specific wavelength, or spectrum, of light to fingerprints on
windowsills, doors handles, railings and other surfaces at crime scenes.
Another technique used to discover latent prints is cyanoacrylate processing or fuming. Cyanoacrylate processing (super glue) or fuming can
be done before or instead of using fingerprint powder. This process works best
on nonporous surfaces. This process involves exposing an object to
cyanoacrylate vapor(fumes). If latent prints are available, the vapor will
stick, and the prints will be detected using a light source.
After fingerprint analysis has collected all
fingerprint evidence, they compare them with those collected from the scenes of
similar crimes. Fingerprints are compared by fingerprint analysis to recent
crimes to see if similarities arise. Today, a computer database known as the
"automated fingerprint identification system" allows new fingerprints
to be added and compared to existing fingerprints. The system has allowed
faster fingerprint matches to be found to those already on file.
Finger
Prints and Identical Twins.
Let's Practice
Fire Investigation
Figure 4 Pexels
Around the world and in
the United States, fires cause major injuries, property destruction, and death.
A Fire investigator conducts investigations at the scene of fires and
collects and studies
evidence to determine if it was accidental or deliberately set (arson). There are many reasons why a
person would commit an act of arson. Some of these
reasons include
obtaining insurance money to cover up a crime at the site, being angry with a
homeowner or someone who lives there, and senseless vandalism.
Many fire investigators
have degrees in fire science or forensic science specialty such as chemistry.
In the past, firefighters and others who were not trained in forensic
science conducted fire
investigations. Traveling is an important part of a fire investigator's job,
ideally traveling to the fire scene while the fire is still burning. Once on
the scene, they gather
evidence, observe the properties of the fire (if it is still burning), and
interview witnesses. Shortly after, they review pictures and videos of the
scene before, during,
and after the fire. They finish off by writing reports and testifying in court.
All while working together with the police to identify arson suspects. They
also prepare damage
estimates for reporting and insurance purposes.
For more information
about fire investigation
International
Association of Arson Investigators
International
Association of Bomb Technicians and Investigators
National Association of
Fire Investigators
Forensic Anthropology
A physical
anthropologist who studies human remains is called Forensic anthropologists.
Forensic anthropologists work at the site of car, plane, or train crashes,
suspected
crime scenes,
laboratories, and many other locations.
One of the first things forensic anthropologists do is determine if
remains are human, animal, or a mixture of the two.
It determined that the
remains are human, so the forensic anthropologist starts to create a biological
profile of the deceased. The biological
portfolio estimates the
deceased age (looking
at teeth), sex, height, and in some cases, ancestry (ethnic descent). Creating
a biological profile helps forensic anthropologists and law enforcement
narrow down the people
missing in a particular area. A particular test, like x-rays, DNA analysis, and
dental record analysis, helps narrow it to a small
number of individuals
with similar characteristics. Afterward, they attempt to conclude the cause of death.
However, a forensic
anthropologist does not always have a body. Sometimes, law enforcement
officials ask for forensic anthropologists' expertise in crime
scenes and environments
to look for a body or mass graves in a specific area. After locating a body,
they use modified archeological techniques to recover the body and
evidence. They then
study the body, create a biological profile and attempt to identify the person.
Forensics
anthropologists work in many different settings aside from crime scenes. Some
work in museums cataloging and curating ancient human remains. Others work
in specialized areas
such as facial reconstruction, where they attempt to recreate the appearance of
an unidentified person using features from their skull.
New Forensic
Technique May Better Gauge Age at Death | Discovery Education
To learn more about forensic anthropology:
American
Anthropological Association
American Board of
Forensic Anthropology
Forensic Ballistics
Within forensic science, there is a specialized
area in firearm investigation and ballistics. According to CrimeMuseum.org,
ballistics is the "study of motion, dynamics, angular movement, and
effects of projectile units (bullets, missiles, and bombs)." Fire
investigation and firearms investigators often study guns and the bullets they
fire. Every time a gun is fired, they produce microscopic marks on the surface
of bullets and cartridge cases. Scientists study these marks to link bullets
and cartridge cases to suspected criminals after a crime. They often testify in
legal proceedings about their findings. During testimony, they explain how
firearms and ammunition work. Some questions they might answer:
·
What kind of firearm was used in the alleged crime?
·
What kind of ammunition was used?
·
What position was the bullet fired from? (helps determine if
this was suicide, accident, self-defense, or homicide).
To learn more:
https://after.org/about-us/what-is-afte/what-is-firearm-and-tool-mark-identification.
Complete the questions for
this section.