Real-life CSI - Bloodstain Analysis

This lesson is designed to build students’ competencies in the following skills:

• communication
• critical thinking
• collaboration
• problem solving
• ethical understanding.

Australian Curriculum content descriptions (v9): 

Year 10 Science:

• investigate how advances in technologies enable advances in science, and how science has contributed to developments in technologies and engineering (AC9S10H02)
• examine how the values and needs of society influence the focus of scientific research (AC9S10H04)

Syllabus outcomes: SC5-12ES, SC5-13ES

General capabilities: Critical and creative thinking, Ethical Understanding, Literacy

Relevant parts of Year 10 achievement standards: Students analyse the relationship between science, technologies and engineering. They analyse the key factors that influence interactions between science and society.

This lesson is part of the wider unit of work: Real-life CSI – Secondary 

Time required: 65 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

These materials are per group. Suggested group size of two to three students.

Experiment 1: Release height

• graph paper
• measures: 30cm and 100cm rule
• newspaper
• pencil
• pipette or bottle with eye-dropper (something that will accurately deliver one drop of fluid with a consistent volume)
• plain paper (to make label sheets)
• stand and clamp – something to attach the pipette or bottle holding the synthetic blood.
• synthetic blood (see https://www.scribd.com/document/156835304/FSB06 for recipes).

Experiment 2: Impact surface

• graph paper
• pencil
• materials with different surfaces. E.g., cardboard, plastic bag, ceramic tile, carpet square, paper towel, wood, newspaper, metal, clothing (socks, jeans, T-shirt, etc.)
• measures: 30cm and 100cm ruler
• pipette or bottle with eyedropper
• stand and clamp
• synthetic blood (see https://www.scribd.com/document/156835304/FSB06 for recipes).

Experiment 3: Direction of travel

• 30cm rulers
• pencils
• plain paper to make copies of:
  • Sheet A: A prepared sheet of bloodstains with information about how the bloodstains were created
    • dip a toothbrush in the simulated blood and fling droplets from the toothbrush as your arm moves across the paper in a definite direction, e.g. R→ L
    • label the paper with a general description of the action. E.g. R→ L direction, with the angle changing from shoulder to paper level
  • Sheet B: A prepared sheet of bloodstains with NO information about how the bloodstains were created
    • dip the toothbrush in the simulated blood
    • place your elbow on the table, and, using a protractor, position your arm at a predetermined angle, eg 45 degrees.
    • keeping the arm at the measured angle, fling droplets off the toothbrush as your arm moves across the paper, e.g. R→ L
    • do not provide a description of your actions, but make sure you record them for later
• synthetic blood (see https://www.scribd.com/document/156835304/FSB06 for recipes)
• Student Worksheets (one per group)
• toothbrush.

This is an original Cool+ lesson.