Quick summary: In this lesson, students will learn about trace evidence and how forensic scientists use it in forensic investigations. They will also learn about some of the limitations of using physical evidence and some of the technology involved in obtaining/analysing it.
- Students will understand what physical evidence is
- Students will understand how forensic scientists use physical evidence in their investigations
- Students will understand the limitations of using physical evidence
- Introduce students to some of the technology used to obtain and analyse physical evidence.
21st century skills:
Australian Curriculum Mapping
Year 10 Science
- Scientific understanding, including models and theories, is contestable and is refined over time through a process of review by the scientific community (ACSHE191)
- People use scientific knowledge to evaluate whether they accept claims, explanations or predictions, and advances in science can affect people’s lives, including generating new career opportunities (ACSHE194)
Relevant parts of Year 10 achievement standards:
Students evaluate the validity and reliability of claims made in secondary sources with reference to currently held scientific views, the quality of the methodology and the evidence cited. They construct evidence-based arguments and select appropriate representations and text types to communicate science ideas for specific purposes.
This lesson is part of the wider unit of work: Real-life CSI – Secondary
Time required: 60 mins.
Level of teacher scaffolding: High – there is likely to be quite a lot of explanation needed, as well as students requiring assistance during the practical part of the lesson.
Note: In this lesson, there is an opportunity to create a ‘real’ crime scene for students to inspect for evidence. If this is the case, you’ll need to set it up and have it ready to go before the students walk into the classroom.
- Analysing Trace Evidence Worksheet (one copy per group)
- Collecting Trace Evidence Worksheet (one copy per group)
- Device capable of presenting video to the class
- Sticky notes.
- Printed copies (one per group) of crime scene OR real-life crime scene set up in the classroom
- Sticky notes
- A “mini” crime scene in a plastic tub or cardboard box (as shown in the photo) per group containing the following things:
- Animal blood from a meat tray on a “murder weapon” (e.g. a cotton bud)
- Corn syrup blood OR animal blood from a meat tray to make blood splatters
- Human hair (Hint: you could have two if you wanted – one from the victim and one from the perpetrator)
- Small doll
- Small plastic or glass cup with fingerprints on it (Hint: A small lab beaker should work!)
- Toy car and ink (to make tyre tracks)
- Collecting Trace Evidence Student Worksheet
- Evidence bags/bottles
- Hairnets (optional)
- Magnifying glass
- Rubber gloves.
- Analysing Trace Evidence Student Worksheet
- Microscope slides and coverslips
- 3% hydrogen peroxide in a dropper bottle (these can be purchased from chemists)
- Phenolphthalein in a dropper bottle (these can be purchased from school science suppliers)
- Sticky tape
- Container of powder (cocoa, talcum powder or similar)
- Fingerprint “database” (i.e. a piece of paper with five different ink fingerprints labelled ‘suspect 1-4’ and ‘victim’).
- Five different toy cars labelled ‘Suspect 1-4’ and ‘victim’
- Hair sample “database” (i.e. five pre-prepared microscope slides labelled Suspect 1-4 and victim).
Keywords: Forensic Science, Crime Scene Investigation, Evidence, Trace Evidence, Fingerprints, Impressions, Blood splatter, Kastle-Meyer Test, Hair, Science, STEM, STEAM, photography.
Cool Australia’s curriculum team continually reviews and refines our resources to be in line with changes to the Australian Curriculum.