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Lessons Assignments Fingerprints The BasicsA fingerprint is a the pattern of ridges and furrows on the surface of the fingertip, that have been used to identify victims and criminals for hundreds of years, ever since it was first used to secure a conviction in 1902.?The basis of fingerprinting is very basic. Each person's fingerprints are said to be unique. These friction ridges exist to assist in our ability to grasp and hold onto objects.?These ridge patterns (also known as minutiae) and details of the ridges have so far never been repeated.?The ridges on our fingertips are developed prior to birth, as a fetus, and are persistent throughout our life, with the exception of any permanent scarring that may occur. Different patterns in the ridge details occur at different rates, which allow for classification - known as the Henry System.? To go into a bit more depth - our skin is one of the largest organs of the human body and it combines layers of tissue which function together. There is the epidermis- the outer layer of?skin, and the dermis - the inner layer. The friction ridges can be seen on the outer layer of skin, and can be found on the digits, the palms of your hands and even the soles of your feet. A?footprint can be as telling as a fingerprint or a palm-print. However, there currently is no database for footprints, like there is for fingerprints. To be able to use a footprint as evidence you would first need a suspect, have them brought in to be printed, and then have the two prints examined. There are pores along the friction ridges which leave behind a oil - this is what makes dusting for prints possible. In cases where the epidermis has been removed, it is possible to read the ridges from dermal layer. If both layers are damaged, it will leave a scar behind, which can be used as a unique feature.?Fingerprint DetailsIn the Henry system, developed by Sir Edward Richard Henry in 1897, there are different levels at which an investigator can identify patterns.?Level 1 Detail - A general overview of the friction ridge flow, structural information and patterns on the finger/palm.?Level 2 Detail - Individual friction ridge paths and friction ridge events, such as bifurcations, ending ridges and dots.?Level 3 Detail - Friction ridge dimensional attributes, such as width, edge shapes and pores.?One of the issues with fingerprints though is that there is no set criteria for what defines a "match". Different countries have different standards, but even these can change from case to case. An average fingerprint has as many as 150 individual ridge characteristics. At one point in time in North America, you were required to identify 8 particular points on a print to secure a match. Now however this has changed to as long as you can see Level 3 Details, that's enough to secure the match. In essence, you must have observed sufficient uniqueness to establish individuality.?The amount of surface area required to make match is only the size of the hole punched in a piece or paper. It's not how big the surface area is, but what's inside it!Fingerprint PatternsThis is the meat and potatoes of fingerprinting. This is what it all comes down to. The details of a fingerprint are also broken down into categories. I've tried to include as many examples as possible, to give you the best overall picture.Level 1 Details include:Loops - characterized by ridge lines that enter from one side of the pattern and curve around to exit from the same side, and must have 1 delta (a delta is the ridge point?closest to the type-line divergence). 60-65% of the population have loops.? Ulnar loop - the loop opens toward the little finger. Radial loop - the loop opens toward the thumb(Of course this picture depends on which hand you are looking at!)Whorls - includes ridge patterns that are generally rounded or circular or even spiral in shape and have at least 2 deltas. 30-35% of the population have whorls. Plain whorls and central pocket loops (which does count as a whorl despite the name!) - have at least one ridge that makes a complete circuit; can be a spiral, oval or variation. If an imaginary line is drawn between the two deltas touches any one of the spiral ridges the pattern is plain. If no ridge is touched, the pattern is a central pocket loop.? Double loop - made up of two loops combined into one fingerprint. Accidental - contains two or more patterns or a pattern not covered by other categories. It can consist of loops, whorls, and arches.?Arches - characterized by ridge lines that enter the print from one side and flow out the other side. Arches do not have any deltas. 5% of the population have arches.? Plain arch - formed by ridges entering from one side and exiting on the other side of the print. They tend to rise in the center of the pattern to form a wavelike picture.? Tented arch - is similar to the plain, but instead of rising smoothly at the centre, there is a sharp spike or the ridges meet at an angle less than 90 degrees.?Level 2 Details include (and are listed most common down to least common): Ridge endings - a ridge will suddenly end in the middle of a print. Bifurcations - when a single ridge divides into two separate ridges. Dots - exactly what you think it is. A dot in the middle of the pattern Enclosures - a single ridge divides into two ridges, and then the two ridges come back together again to reform the single ridge.Level 3 Details (which is individual ridge detail) includes:The individual ridges are magnified and examined. Pores and ridge width are examined, and areas can be convex, concave or open.? Using a brush and powder to find the latent print (invisible prints) can destroy the details, and they also don't produce good level 3 details. Your best option would be to take a good, clear photograph.?Other NotesFingerprints are collected by police officers and entered into an Automated Fingerprint Identification System (AFIS). In 1999, the FBI began an operation which linked state AFIS?computers to the FBI database and named it the Integrated Automated Fingerprint Identification System (IAFIS). AFIS uses automatic scanning devices that convert the image of a fingerprint into digital minutiae that show ridges at their points of termination (ridge endings) and the branching of two ridges (bifurcations). The computer stores each fingerprint in the form of a digitally recorded geometric pattern. The computer can make thousands of comparisons in a second. It uses a scoring system that assigns prints to each of the criteria as set by an?operator. If compiles a list that have a close correlation to the search prints, and then all of those prints are examined by a trained fingerprint expert who makes the final verification. AFIS does not actually make a final decision on whether a print is a match - unlike what you will see on "CSI"!?Case FileTaken from Criminalistics - An Introduction to Forensic Science, by Richard Saferstein: Since his arrest in 1968 for the assassination of Dr. Martin Luther King Jr., endless speculation has swirled around the motives and connections of James Earl Ray. Ray was a career criminal who was serving time for armed robbery when he escaped from the Missouri State Prison almost one year prior to the assassination. On April 3, 1968, Ray arrived in Memphis, Tennessee. The next day he rented a room at Bessie Brewer's Rooming House, which was situated across the street from the Lorraine Motel where Dr. King was staying.?At 6:00pm, Dr. King left his second story motel room and stepped onto the balcony of the Lorraine Motel. As King turned toward his room, a shot rang out, striking the civil rights activist. Nothing could be done to revive him and Dr. King was pronounced dead at 7:05pm. As the assailant ran on foot from Bessie Brewer's, he left a blanket-covered package in front of a nearby building and then drove off in a white Mustang. The package was later shown to contain a high-powered rifle equipped with a scope, a radio, some clothes, a pair of binoculars, a couple of beer cans, and a receipt for the binoculars. Almost a week after the shooting, the white Mustang was found abandoned in Atlanta, Georgia.?Fingerprints later identified as James Earl Ray's were found in the Mustang, on the rifle, on the binoculars, and on a beer can. In 1969, Ray entered a guilty plea in return for a sentence of 99 years. While a variety of conspiracy theories surround this crime, the indisputable fact is that a fingerprint put the rifle that killed Martin Luther King Jr. in the hands of James Earl ments _displayNameOrEmail_ - _time_ - Remove_text_ ................
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