What do you know about forensic science? Do you know how long people have been using fingerprints in crime scenes?
In the 1890s Francis Dalton wrote about fingerprints and proved that each person has a unique print that stays the same all their life.
Argentina was the first country in the world to use fingerprinting in criminal cases and in 1904 the New York City police force began collecting fingerprints of criminals. In 1910 in France, the first crime lab opened and it used scientific techniques to examine evidence.
This fourth section contains 3 steps. Work them through step by step.
Step
Activity
1 Speaking (and Reading)
Make a list with your classmate about types of forensic evidence etc. Complete the chart. Read a text about trace evidence. Answer the questions.
2 Reading
Read the text. Do the exercise. Watch a video and answer questions: true or false. Complete the transcript.
3 Task
Follow instructions and write your own crime report.
De onderstaande antwoorden moet je zelf nakijken; vergelijk jouw antwoorden met de goede
antwoorden, en geef aan in welke mate jouw antwoorden correct zijn.
Read the text and choose the correct words in the exercise.
High fashion detective work. By Catriona Jenner Harvey.
Lipstick has many uses: it makes you look chic, adds color to an outfit, and — scientists have discovered — helps solve crimes.
In the same way as fingerprints are extracted from crime scenes and analyzed to provide clues about the perpetrator, experts are now discovering that they can do the same with lipstick.
Although attempts have already been made to extract lipstick from surfaces, they have involved 'X-ray refraction' or 'Raman spectroscopy' and have been hugely time consuming, confusing, and costly.
But now experts are using 'gas chromatography' to help the process, according to Medical Daily. Apparently this involves adding an organic solvent to extract the oils and waxes from the lipstick, and then adding a basic organic solvent to remove any of the remaining residue. While the scientists at Western Illinois University, who are researching the matter, are currently just lifting samples from paper, they hope to extend this to all sorts of materials and surfaces from a crime scene in the future.
So there's a lesson to be learned here, one and all: Don't wear lipstick when you're off to commit a massive crime because chances are you'll get a smudge of it somewhere, and the feds will be right on your tail.
Feels like there's a movie in there somewhere...
Source: http://www.seventeen.com
Exercise: Lipstick can now be used to solve crimes
Exercise: Lipstick can now be used to solve crimes
De onderstaande antwoorden moet je zelf nakijken; vergelijk jouw antwoorden met de goede
antwoorden, en geef aan in welke mate jouw antwoorden correct zijn.
Watch and listen to the video again. Complete the transcript.
It’s a common TV crime show trope: no suspects, little .....[1]..... until an investigator finds a lipstick mark.
The sample is sent away to the lab and boom! the suspect is in .....[2]...... .
In reality, forensic analysis is not that fast or straightforward but scientists are making progress. Brian Bellot and his team at Western Illinois University have developed a new to lift lipstick samples and found the best way to .....[3]..... them. They’re presenting their research at a meeting of the American Chemical Society in San Diego. .....[4]..... and analyzing lipstick samples can often require costly equipment and specialized training. “My method can actually be .....[5]..... by a bachelor’s level or even a master’s level student or scientist.
They just have to cut off the sample, simple extraction procedure, something they would learn in sophomore .....[6]..... chemistry." They simply add an organic solvent to get rid of the oils and waxes. Then add a different solvent to lift the remaining residue. The team then .....[7]..... gas chromatography to find molecules unique to forty .....[8]..... brands of lipsticks.
"Each lipstick has at least two or three components which are different from the rest.” Bellet says forensic labs can
adopt this new .....[9]..... as is, with no new equipment or training needed.
He also says his lab is working on expanding the library of samples so crime labs everywhere can use his new .....[10]..... chemistry to pin perps.
Now compare the video and the text. Is there any extra or different information?
Step 3 - Task
Task
You are going to study a crime scene of your own.
Follow the instructions.
See how many clues you can identify in your own "crime scene".
Choose a room (e.g., kitchen, living room, bedroom) or part of a room and go over it carefully, finding any trace evidence such as hair, clothing fibers, and chips of paint. You can collect these with a pair of tweezers and place them in envelopes or Ziplock bags to identify later. Are there any prints or scuff marks on the floor from shoes? Bits of soil or rock that might have been brought in?
To be thorough, record all of these clues. Make sketches in an investigation notebook if you want to.
If you have a microscope, compare different kinds of hair at high power magnification. (You can also use a 10x or stronger magnifying glass.)
Examine different cloth fibers, too - try cotton, wool, and rayon or acetate.
Make a wet mound of the hair or fibers by putting a drop of water on a microscope slide, adding the specimen, and pressing a cover slip down on top. What does each specimen look like? Is it
smooth or rough? How do the ends look? Compare miscellaneous hair and fibers you
pick up from the carpet or couch. Can you tell what kinds of fibers they are? Where did
they likely come from? Are they all the same? Do you know who or what they belong(ed) to?
Check out any dental evidence in your crime scene.
Then, if you have some willing suspects, make impressions of their bites and compare the
impressions to the evidence you found. A simple way to make impressions is to carefully
bite down into an apple or other soft food, but you can also bite into a folded sheet of white
paper with a piece of carbon paper inside.
Be sure to get both back and front teeth in the bite impression.
Write up your crime scene report.
Click here to download your crime scene report.
Answers
B4 Forensic science
Step 1 Speaking
Which school subject helps you:
Subject
identify DNA
Biology
work out where the bullet came from
Physics
work out where the body was buried
Earth science
identify drugs
Chemistry
(Possible) Answers:
identify which part of the body the hair was from (arms/legs etc.), animal hair – so you would know if animals had been there.
Hair color can help to identify a suspect.
If the hair is human, or from a wig.
Read more at https://www.fbi.gov/
Step 2 Reading
Transcript:
evidence
Handcuffs
analyse
Lifting
run
organic
uses
different
process
cosmetic
Extra or different information in the video:
We learn that they are presenting their research at a conference and that their new method can be carried out by a bachelor/masters level student, implying that the current methodology is complex.
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Arrangement
Oefeningen en toetsen
True or false?
Lipstick can now be used to solve crimes
IMSCC package
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