OCR AAQ Applied Science • F185 • Lesson 9 • Task 1 preparation

Collect, Package and Protect the Evidence

Choose a recovery method that fits the evidence, then keep the sample separate, labelled, preserved and traceable.

📖 NIST Trace Evidence Recovery Guidelines▶ How to Properly Swab DNA Evidence (9 min)▶ Fingerprint lifting – WIRED▶ Evidence Collection & Storage (7 min)▶ Chain of Custody (2 min)
By the end

You should be able to…

  • select suitable recovery methods including swabbing, forceps, tape, scraping and print lifting
  • explain why recovery order and tool changes reduce contamination or loss
  • select sensible packaging and labelling for common evidence
  • explain the purpose of the chain of evidence
Why shouldn't every evidence item go into the same plastic bag?
Collection toolkit

Recovery method must match the evidence

Click each information panel. It opens straight to the information — no extra reveal.

🧪SwabbingSuitable residues or stains on surfaces.Click for information
🗜️Forceps / tapeSmall hairs, fibres and loose trace material.Click for information
🥄Scraping / containersPaint flakes, dried material or soil where appropriate.Click for information
🖐️Print liftingRecover developed fingerprint detail using a suitable method.Click for information
Plan, do not memorise one universal recovery order. Protect fragile/transient evidence, minimise contamination/loss and document before disturbing the scene.
After recovery

Package → label → store → transfer

Separate

Keep evidence items separate to reduce cross-contamination.

Package

Choose a container that protects that specific material.

Label

Use a unique ID and clear recovery details.

Chain

Record each transfer so the evidence remains traceable.

Teacher model

Choose a collection method

Practice scene: a loose hair on a clean desk, a dry paint flake beneath it, a red smear on a hard surface and a developed fingerprint on glass.

Why should tools and containers be changed between samples?
Guided practice

Match evidence to a sensible method

Press start

Work through the cases one at a time.

These are parallel practice examples, not the live set assignment.

Independent consolidation

Packaging Error Hunt

Identify the problem and improve each plan:

  1. Three fibres from different locations are placed together in one bag.
  2. A biological swab is stored without following the centre's approved drying/storage procedure.
  3. A paint flake is collected before its location is photographed.
  4. An evidence label says only “hair”.
  5. A sample is handed to another person without recording the transfer.

Review notes

  • OCR recovery methods include swabbing, forceps, taping, brushing/vacuuming, marks/impressions and print lifting.
  • Select the method for evidence type, condition and surface; no technique is universally best.
  • Use clean/separate tools and containers as appropriate to reduce cross-contamination.
  • Document evidence before recovery and consider order to reduce damage/loss.
  • Packaging should prevent contamination, loss and degradation and must suit the material/condition.
  • The chain of evidence records collection, possession, transfer and storage to protect integrity.

Glossary

Why this matters for Task 1

P2 explicitly requires recovery of trace materials plus packaging, labelling, storage and transport, with equipment sizes/quantities, PPE and repeats. M1 asks why those choices are suitable.

Final checkpoint

Lesson 9 quiz