What is the main purpose of the luminol test at a crime scene?

The luminol test is primarily used to detect trace amounts of blood at a crime scene. This test works by reacting with the iron found in hemoglobin, a component of red blood cells. When luminol is applied to a surface and comes into contact with blood, it produces a luminescent glow in the dark, which allows investigators to identify areas where blood may be present, even if it has been cleaned or is no longer visible to the naked eye.

This capability is particularly useful in crime scene investigations, where blood evidence may not be readily apparent. The ability to reveal blood traces, especially in low-light conditions or on surfaces that would otherwise obscure the presence of blood, makes luminol a valuable tool for forensic analysis. This underscores the importance of luminol in establishing links to potential suspects or victims based on the presence of blood at a scene, even when direct evidence may be scarce.

Other options, while they describe techniques or methods relevant to forensic science, do not align with the specific function of luminol, which is dedicated to identifying blood evidence.