fingerprints

The IAFIS

Provides digital, automated fingerprint searches, latent searches, electronic storage of fingerprint photo files, and electronic exchange of fingerprints and test results.

Cyanoacrylate(super glue)

Surface is nonporous and reaction is heated vapors react with amino acids and proteins found in sweat Resulting in turning all white.

Dusting

Surface is nonporous. Reaction is a powder clings to the perspiration, resulting in a black or fluorescent (collect with tape)

Iodine (paper print)

Surface is porous the reaction is amino acids in sweat but it has a completely diff result. Results in it turns brown.

Ninhydrin (spray and steam)

Surface porous and react with amino acids in sweat (chemical reaction) resulting in turning purple.

Loops

Enter from either the right or the left and exit from the same side they enter. Loops occurrence is 65%.

Purpose of ridges on fingerprints-

Every individual, including identical twins, has a unique fingerprint resulting from unique ridge patterns called minutiae (because the details are so small) .

What fingerprints are composed of grasping?

Fingerprints help us with our grip on objects that we touch. When these ridges press against things, they leave a mark, an impression called a fingerprints.

Arch

Have ridges that enter from one side of the fingerprint and leave from the other side with a rise in the center. Arch occurrence is 5%.

Latent

Hidden prints, are caused by transfer of oils and other body secretions onto a surface.

Plastic

Impression of prints in soft materials(soap), clay, and putty.

Identify what types of evidence fingerprints are?

Individual evidence and physical evidence.

Thomas Jennings case

Laid the groundwork for forensic fingerprint identification in America. By 1925, virtually every court in the United States accepted this form of impression evidence as proof of guilt. In medicine, illness leads to cures, and in law enforcement, murders produce advances in forensic science.

Whorls

Look like a bull's eye, with two deltas(triangles). Whorls occurrence is 30%.

Explain how and when fingerprints form?

The fingerprint is formed in the womb, latest information suggests that the patterns are probably formed at the beginning of the 10th week of pregnancy. Fingerprints consist of natural secretions of the sweat glands that are present in the friction ridge of the skin. These secretions are a combination of mainly water, oils, and salts.

Why can't prints be changed?

They form deep in the skin and they grow back.

Patent

Transfer of print in a liquid to a surface(blood). Visible prints are left on a smooth surface when blood, ink, or some other liquid comes in contact with the hands and is then transferred to the surface.