Case Study-BTK Murders

Dennis Lynn Rader was the killer who murdered 10 people in and around Wichita, Kansas in America. BTK stands for Blind, Torture and Kill which was the way Dennis operated his murders.
His victims were these 10 people:
1974: Four members of the Otero family
Joseph Otero
Julie Otero, Joseph's wife
Joseph Otero II, son
Josephine Otero, daughter
1974: Kathryn Bright (he also shot Bright's brother twice, but he survived)
1977: Shirley Vian
1977: Nancy Fox
1985: Marine Hedge
1986: Vicki Wegerle
1991: Dolores Davis

DNA Fingerprinting

The chemical structure of everyone's DNA is the same. The only difference between people (or any animal) is the order of the base pairs. There are so many millions of base pairs in each person's DNA that every person has a different sequence.
Using these sequences, every person could be identified solely by the sequence of their base pairs. However, because there are so many millions of base pairs, the task would be very time-consuming. Instead, scientists are able to use a shorter method, because of repeating patterns in DNA.
These patterns do not, however, give an individual "fingerprint," but they are able to determine whether two DNA samples are from the same person, related people, or non-related people. Scientists use a small number of sequences of DNA that are known to vary among individuals a great deal, and analyze those to get a certain probability of a match.

Pictures of fingerprints

Fingerprint patterns

There are three main fingerprint patterns;loops, whorls and arches.

Arches are found in around 5% of fingerprints.The lines run fron one side to the other of the pattern, making no backward turn.There are four types of arch patterns: plain arches, radial arches, ulnar arches and tented arches.Plain arches have an even flow of ridges from one side to the other of the pattern. The ridges of radial arches slope towards the thumb, have one delta and no re-curving ridges. On ulnar arches, the ridges slope towards the little finger, have one delta and no re-curving ridges. Tented arches have an angle, an up thrust, or two of the three basic characteristics of the loop.

Loops occur in about 60-70 % of fingerprint patterns encountered. One or more of the ridges enters on either side of the impression. The flow of the pattern in radial loops runs in the direction of the radius (toward the thumb). Ulnar loops are named after the ulna, a bone in the forearm. The ulna is on the same side as the little finger and the flow of the pattern in a ulnar loop runs in the direction of the ulna (toward the little finger).

Whorls are seen in about 25-35 % of fingerprint patterns encountered. In a whorl, some of the ridges make a turn through at least one circuit.There are four types of whorl patterns. Plain whorls consist of one or more ridges which make or tend to make a complete circuit with two deltas, between which an imaginary line is drawn and at least one re-curving ridge within the inner pattern area is cut or touched. Central pocket loop whorls consist of at least one re-curving ridge. Central pocket loop whorl ridges make one complete circuit which may be spiral, oval, circular or any variant of a circle. Double loop whorls consist of two separate and distinct loop formations with two separate and distinct shoulders for each core. Accidental whorls consist of two different types of patterns with the exception of the plain arch.

What is a fingerprint?

A fingerprint is an impression of the friction ridges on finger. Fingerprint ridges are formed during the third to fourth month of fetal development. The ridges begin to develop on the skin of the thumbs and fingers.The purpose of these ridges is to give the fingers a firmer grasp and to avoid slippage. These ridges allow the fingers to grasp and pick up objects.
The friction ridges on the fingers arrange themselves in more or less regular patterns with ridge characteristics. All fingerprints have a unique combination and arrangement of patterns and ridge characteristics.There are three main types of fingerprint; visible prints, latent prints, and impressed prints:

• Visible prints

Visible prints are also called patent prints and are left in some medium, like blood, that reveals them to the naked eye. They can be when blood, dirt, ink or grease on the finger come into contact with a smooth surface and leave a friction ridge impression that is visible without development.

• Latent prints

Latent prints are not apparent to the naked eye. They are formed from the sweat from sebaceous glands on the body or water, salt, amino acids and oils contained in sweat. The sweat and fluids create prints must be developed before they can be seen or photographed. They can be made sufficiently visible by dusting, fuming or chemical reagents.

• Impressed prints

Impressed prints are also called plastic prints and are indentations left in soft pliable surfaces, such as clay, wax, paint or another surface that will take the impression. They are visible and can be viewed or photographed without development.

The History of Fingerprints

Fingerprints were first used in England in July 1858, when Sir William Herschel, Chief Magistrate of the Hooghly district in Jungipoor, India, first used fingerprints on native contracts. With no thought toward personal identification, Herschel had Rajyadhar Konai, a local businessman, impress his hand print on a contract. Personal contact with the document, they believed, made the contract more binding than if they simply signed it. This means, fingerprints are now used because of, not scientific evidence, superstitious beliefs.

Juan Vucetich made the first criminal fingerprint identification in 1892. He was able to identify Francis Rojas, a woman who murdered her two sons and cut her own throat in an attempt to place blame on another. Her bloody print was left on a door post, proving her identity as the murderer.