FORENSICS
1) Fill this table.
the 5 evidences on this crime
scene
(write the words in English and in the phonetic alphabet)
|
The relevant techniques to collect the
clues on the crime scene
(write the words in English and in the phonetic alphabet)
|
In which lab the clues are analysed
(write the words in English and in the phonetic alphabet)
|
|
|
|
a blood stain /blʌd steɪn/
| Photography ;
/fəˈtɒgrəfi/
measurements and
/ˈmeʒəmənts/
diagrams ;
/ˈdaɪəgræm/
polilight ;
/ˈpɒlɪlaɪt/
taking samples .
/ˈteɪkɪŋˈsɑːmpls/ |
Genetics
laboratary
/dʒɪˈnetɪks ləˈbɒrətəri/
|
a fingerprint /ˈfɪŋgəprɪnt/
| Photography ;
measurements and diagrams ; polilight ;
taking samples ;
revealing prints. | Fingersprints
laboratry
|
traces of accelerants /treɪsiz ɒv ækˈselərɒnt]
| Photography ;
measurements and diagrams ; taking samples. |
Chemestry laboratry
/ˈkemɪstrɪ ləˈbɒrətəri/
|
a bullet /ˈbʊlɪt/
| Photography ;
measurements and diagrams ; taking samples . |
Ballistics
laboratry
/bəˈlɪstɪks ləˈbɒrətəri/
|
textile fibers
/ˈtekstaɪl ˈfaɪbəʳs/
| Photography ;
measurements and diagrams ; polilight ;
taking samples . |
Chemistry
laboratry
|
2) Find the appliances used in these labs (write the words in English and in the phonetic alphabet)
In a genetics laboratory;
In a chemistry laboratory;
In a fingerprint laboratory;.
In a ballistics laboratory.
In the genetic lab, you need:
- a micropipette /ˈmaɪkrəʊpɪˈpet/
- a PCR.
- an electrophoresis /ɪˌlɛktrəʊfəˈriːsɪs/
In the chemistry laboratory, you need
- a chromatograph /ˌkrəʊməˈtɒɡrəfɪ/
- A mass spectrometer /mæs spɛkˈtrɒmɪtə/
In a fingersprints laboratory, you need
- powders /ˈpaʊdə/
- a computer /kəmˈpjuːtə/ ( a data base). /ˈdeɪtə beɪs/
In a ballistics laboratory, you need:
- a water tank.
- an Ibis hub /hʌb/. (Integrated
ballistic identification System).
3) Write a short explanation of what scientists do in genetics and chemistry laboratories (computers with an even number) or in fingerprint and ballistics laboratories (computers with an odd number).
In the
genetic lab, a scientist analyzes samples like blood, saliva, hair… He/she uses
a micropipette to collect very little quantities of material which contain DNA.
Then the DNA is purified, and the quantity of DNA in increased with a PCR.
Finally,
he/she puts some DNA on a gelatinous material in order to be analyzed with an
electrophoresis. In this appliance, an electric current goes through the
gelatinous material and allows the separation of DNA chemicals. The result is a
DNA footprint which is unique for each
of us.
a DNA footprint
In the chemistry laboratory.
The samples which are analyzed in a chemistry lab are alcohol, drugs,
poison, dyes, explosives or other substances collected on the crime scene.
Liquid substances
are analyzed with a chromatograph. The liquid is collected with a micropipette
and diluted.
Then it’s
injected into the chromatograph. The molecules which compose the liquid are
separated according to their weight.
The result of
analysis is a graph. The order of arrival represents their chemical
configuration. The height of the peaks
represents how much there is of this molecule in the sample.
the result of a chromatograph
A mass spectrometer
This appliance is used for solid or liquid samples. Chemicals are bombarded
by electrons so chemicals are broken into tiny molecules. The mass of each molecule
is measured.
The result is a graph on which all the masses of each molecule are represented.
And this graph enables to indentify the chemical.
the result of a mass spectrometer
In a fingerprints laboratory, the scientist uses powders to reveal fingerprints. The powder that
is used depends on the texture, nature and the color of the background. The
revealed fingerprint is photographed next to a scale
Then, the scientist uses a computer to compare the fingerprints with other
prints on the data base.
a fingerprint comparison on a data base
a fingerprint comparison on a data base
In a ballistics laboratory, the scientist fires a shot in a water tank.
Then he/she collects it at the bottom of the tank. (The water slows and stops
the bullet which can be collected intact.)
Then he/she uses an Ibis hub (Integrated ballistic identification System).
It takes photographs of the markings on the bullet and the cartridge case. And
then it allows the comparison of these photographs with the ones on the data
base.
a cartridge comparison on a data base
a cartridge comparison on a data base
a bullet comparison on a data base