Activity Introduction

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.

Learning intentions:

  • 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: 

CommunicatingCritical ThinkingEthical UnderstandingProblem FindingProblem SolvingTeam Work 

Australian Curriculum Mapping

Content descriptions: 

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)

Syllabus outcomes: SC5-12ES, SC5-13ES

General capabilities: Literacy, Critical and Creative Thinking, Ethical Understanding

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.

Topic: STEM

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.

Resources required:

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.

Part A:

  • Printed copies (one per group) of crime scene OR real-life crime scene set up in the classroom
  • Sticky notes

Part B:

Per group:

  • 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
  • Forceps
  • Hairnets (optional)
  • Magnifying glass
  • Rubber gloves.

Part C:

Per group:

  • Analysing Trace Evidence Student Worksheet
  • Microscopes
  • Microscope slides and coverslips
  • Forceps
  • 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)
  • Rulers
  • Fingerprint “database” (i.e. a piece of paper with five different ink fingerprints labelled ‘suspect 1-4’ and ‘victim’).

Per class:

  • 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.


Teacher Worksheet

Teacher Preparation

Learning intentions: Students will

  • ... understand what physical evidence is
  • … understand how forensic scientists use physical evidence in their investigations
  • … understand the limitations of using physical evidence
  • … be familiar with some of the technology forensic scientists use to obtain and analyse physical evidence.

Success criteria: Students can…

  • … identify what physical evidence is and how to obtain and analyse it
  • … identify some of the technology used to gather and analyse physical evidence.

Teacher content information:

The work of a forensic scientist falls into three broad groups. This lesson mostly explores two of the groups:

1. Field (collecting the evidence)

Forensic scientists can find evidence from the crime’s perpetrator at almost every crime scene. Trace (or fragmentary) evidence is any type of material left at or taken from a crime scene, or the result of contact between two surfaces such as shoes and the floor covering o

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Student Worksheet

Thought Starter: 'There is no perfect crime'


Collecting Trace Evidence

Your group has been given a “crime scene” to investigate. You need to use the instructions provided to collect and analyse the trace evidence to try to work out what occurred.


  1. Put on your gloves, lab coat and hairnet to avoid contaminating the crime scene.
  2. Take a photo OR draw a picture of your crime scene before you “enter” it. Place this in the results section.
  3. Write a hypothesis below about what you think has happened at the crime scene, based purely on your observation.
  4. Look for trace evidence.
    1. Carefully place the trace evidence in an evidence bag or bottle, making sure to use your gloved hands or forceps.
    2. Replace each piece of evidence with a numbered label. Record a description of each piece of evidence next to the appropriate number in the Results table.




A photo or picture of the crime scene (staple to this sheet as a separate page)

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