Extended Casework questions

Question 1

Describe the process of KM testing (4 Stages)

Answer 1

KM test - presumptive test which reacts with haemoglobin in blood.
Using filter paper, fold in half and half again, rub onto blood, then unfold (blood should be in centre).
Add ethanol to the stain.
Add KM solution, should remain colourless.
Add hydrogen peroxide - should turn pink immediately to determine presence of blood.

Question 2

Limitations of KM test (3)

Answer 2

False positives - leaving it longer than 30 seconds, naturally oxidises; Horseradish
Cannot tell if blood is human or animal/who’s blood it is
Only a presumptive test - not confirmatory

Question 3

Explain the process of a footwear examination

Answer 3

Complete case assessment and strategy form using the MG21 provided. State any inconsistencies. Apply correct PPE and clean bench, placing paper down onto the bench. Conduct ESLA procedure, then gel lift on mark provided. Take take prints of possible offending shoe. Identify Pattern code and compare using clear photocopies. Photograph each stage of the process, completing notes.

Question 4

Explain the process of using Luminol

Answer 4

Using correct PPE, set up photography in area planning on using Luminol. Turn lights off, spray Luminol and photograph. Blood should fluoresce light blue, becoming visible. Reacts with haemoglobin in the blood. False positives - bleach and gloss.