Investigator williams arrives at a suspected crime scene, then sprays the area with a substance and turns off all the lights in an effort to find bloodstains invisible to normal eyes. what material, equipment, or technique is he using?

He is using luminol.

Explanation:

Luminol is a chemical substance that helps find bloodstains that are invisible to normal eyes. Luminol is a chemical substance that reacts to blood and other substances. The chemical reaction it has with blood it’s that it makes the substance more fluorescent. That is why is use in this type of scenes, because it makes it easier to locate and see all the possible bloodstains. Dry blood reacts better than fresh blood.

Luminol

Explanation:

I took the test, but also the notes say  "With this test, a luminol reagent is sprayed on surfaces or stains to see if blood is present.  If it is, the bloodstain will emit light or luminescence. "

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