Guilty or Innocent?Fingerprints Tell the story.

Your First and Last Name: oct2016-fingerprints tell the story.pdf Click on the thumbnail picture of the article to the left. Use this article to answer the questions the interactive worksheet, you may want to open the article in a separate tab to easily reference. Article: "Guilty or Innocent? Fingerprints Tell the Story." WHEN do fingerprints begin forming? In the womb @ 10 days In the womb @ 10 weeks In the womb @ 10 months Even identical twins have different fingerprints because while they are forming, [because] all the details of the _ in the womb can change how these fingerprints look. DNA Proteins Environment _ Suggests that a person always leaves something behind (and takes something with him or her, too) every time that person interacts with the environment. Cross Contamination Theory Locard's Exchange Principle Particle Transfer Law 3 Types of Fingerprints: Match the following terms with corresponding definitions. Latent Fingerprints Not visible to the naked eye and require processing to become visible. Patent Fingerprints Visible to the naked eye and are left by wet fingers which have blood, ink, oil, or other liquid on them. Plastic Fingerprints Visible to the naked eye, 3-D, and are formed in soft material such as wet paint, clay, wax, soap, etc. Sweat Glands: Why do you leave behind fingerprints? Along each friction ridge is a row of tiny holes. Each of these holes is a pore connected to a sweat gland. Eccrine Glands Most common type of sweat gland, found virtually in all skin, with the highest density on your hands and feet. Sebaceous Glands Secrete an oily substance known as sebum, which keeps your skin waterproof, with the highest density on your face and scalp. What is the composition of sweat? (select all that apply) Amino acids Lipids Salts Sweat Sebum Water What is the composition of a Fingerprint? (select all that apply) Amino acids Lipids Salts Sweat Sebum Water What factors contribute to the quality of a fingerprint left behind? -If your skin is dry, there will be fewer oils on the skin, and the fingerprint left behind will be less distinct.-The type of surface on which the fingerprint is deposited plays a big role in whether a fingerprint can be recovered.-A porous surface (paper or wood) will tend to absorb the fingerprint, making it last longer but also making it harder to visualize.-A nonporous surface (glass, metal, plastic) will leave a more distinct fingerprint; but because a fingerprint is only deposited on a surface, it can be wiped off easily. What is the most common method of revealing latent fingerprints - especially when they are left on a nonporous surface - involves ... Dusting w/ Powder Spraying w/ Luminol Printing w/ Ink Why does fingerprint powder readily binds to latent fingerprints? Both are greasy Both are sticky Both are nonpolar Both are polar How are fingerprints preserved after being revealed by dusting? (select all that apply) Photograph Adhesive tape Sketch Notes What other types of information can be obtained from a fingerprint besides identity? The gender of the person who left a fingerprint can be determined by analyzing the ratio of certain amino acids in a fingerprint's oily residue. Amino acids are excreted in sweat, which shows up in fingerprints. Women have ~ twice as many amino acids in their sweat as men. Finding a Match: When a suspect's fingerprints are run through IAFIS, the computer will return several fingerprints that are the closest match, and then a trained fingerprint analyst will make the final determination. What other types of information can be obtained from a fingerprint besides identity? Recent analysis of fingerprints' oily residues has revealed a method that can determine the age of fingerprints, providing a vital piece of information in determining the time when a crime was committed.A test was also developed to detect traces of cocaine in fingerprints and cocaine metabolites; revealing not only that it was present in fingerprints but also whether it was metabolized by the body.