Question

When is it more appropriate to use presumptive tests in a crime investigation? When is it more appropriate to use confirmatory tests in a crime investigation? Why is hemoglobin important for presumptive tests for the presence of blood?Describe how the Kastle-Meyer test is used to detect blood at a crime scene.

Answer 1

Answer:Phenolphthalein is a presumptive test that reacts with the heme molecule present in blood. A positive reaction gives a pink color. While bloodstains normally appear red-brown in color, the color of the substrate or the age of a stain may affect the appearance or visibility of the stain.

Explanation: