How do you use fingerprint dust?

The various fine dusts used in detecting fingerprints, are chosen such that they will adhere to the oils present in the fingerprints. It is brushed on to the target surface with a brush made of fine hair. This tool should not apply a force that would destroy or distort the fingerprint.

In the field, the print, after demonstration, is lifted on adhesive tape, and this 'replica' is what is examined.

There are other types of detection equipment other than powders.

The elements of a fingerprint that are chosen to analyze are distinct features, such as bifurcations, loops, whorls and similar. These will be counted and their position determined with relation to other features. A match of three features would be have a very low confidence, a five-point match somewhat better, and a seven-point match would be good. But the target fingerprint is often of poor quality.

Indeed, even expert fingerprint readers; when presented with some real fingerprints; do not perform as well as is commonly presented.

The fingerprints of pre-puberty juveniles commonly do not have the oils upon which these tests depend. So children's tests are difficult.