Fingerprint Patterns & Minutiae Notes PDF

Fingerprints Patterns & Minutiae  History of Fingerprints The following is a brief history of fingerprints: 200 BC Fingerprints were used to sign contracts in Babylon 651 AD Chinese historian Kia Kung-Yen states fingerprints can be used to iden...

Fingerprints Patterns & Minutiae  History of Fingerprints The following is a brief history of fingerprints: 200 BC Fingerprints were used to sign contracts in Babylon 651 AD Chinese historian Kia Kung-Yen states fingerprints can be used to identify people 851 AD Abu Zayd Hasan witnessed Chinese merchants using fingerprints to sign contacts on silk merchandise 1788 AD Christopher Mayer concluded that fingerprints were unique to each individual 1892 AD Sir Francis Galton Sir Francis Galton writes a book titled Fingerprints  Case Study: Francisca Rojas On June 29, 1892, Ponciano Rojas and his sister, Feliza Rojas, were found murdered in their home in Argentina They were aged six and four years old Their mother, Francisca, was found alive with a throat wound She blamed the attack on their neighbor Pedro Velazquez The issue was that Pedro had an airtight alibi for that night Francisca’s boyfriend had told her that he would marry her if she was child-free Investigators found a bloody fingerprint on one of the children’s bedroom door and matched it to Francisca She confessed and was convicted of the dual murder Francisca’s fingerprint  Introduction to Fingerprints All fingers, toes, feet, and palms are covered in small ridges These ridges are arranged in connected units called dermal, or friction, ridges These ridges help us get or keep our grip on objects Natural secretions plus dirt on these surfaces leave behind an impression (a print) on those objects with which we come in contact 3 Rules of Fingerprints: Each individual has unique fingerprints, including twins Fingerprints have patterns and can be classified Fingerprint patterns do not change through the lifetime of an individual  Case Study: John Dillinger John Dillinger was born on June 22, 1903 in Indiana B He became one of the most notorious bank robbers during the E F Great Depression O On June 22, 1934, he was named Public Enemy #1 by the FBI R E There was a huge reward with his face being plastered on posters As a result, Dillinger decided to undergo plastic surgery to alter his appearance but it did not change it drastically enough A A doctor recommended that he remove his fingerprints F T In May 1934, Dillinger decided to burn his fingerprints off E R with acid It was not successful with faint ridges still seen on his fingers  Fingerprints: Cores & Delta Fingerprint An impression made on a surface by a person's fingertip The basic fingerprint pattern analysis is broken down into two components: Core the center of a whorl or loop Delta triangular regions By counting the number of deltas, investigators can determine the which of the three fingerprint pattern is present  Fingerprint Patterns There are 3 general fingerprint patterns: Arches Plain Arch Tented Arch Loops Radial Loop Ulnar Loop Whorls Plain Whorl Central Pocket Loop Whorl Double Loop Whorl Accidental Whorl  Arches Arches are the simplest type of fingerprints that are formed by ridges that enter on one side of the print and exit on the other No deltas are present Types of arches: Plain Arch Gentle lines one side to another Tented Arch Pointed lines one side to another Plain Arch Tented Arch  Arches Tented Arch Plain Arch  Loops Loops must have one delta and one or more ridges that enter and leave on the same side These patterns are named for their positions related to the radius and ulna bones i.e. the bone the loop opening is facing towards Types of Loops: Radial opens toward the thumb Ulnar opens toward the “pinky”  Left v. Right Hand Loops LEFT HAND RIGHT HAND  Whorls Whorls have at least two deltas and a core Types of Whorls: Plain Whorl Symmetrical, 2 deltas Central Pocket Loop Whorl Asymmetrical, 2 deltas Double Loop Whorl “S” shape, 2 deltas Accidental Whorl All others not covered, 3 or more deltas  Whorls Central Pocket Loop Whorl Double Loop Whorl Plain Whorl  Case Study: Clarence Hiller On September 19, 1910, Clarence Hiller woke up in Chicago Thomas Jennings to his wife and daughter being attacked by an intruder They fought and fell down the staircase Hiller was shot three times by the attacker and died on scene A man was stopped less than a mile away with a torn and bloodied coat with a revolver He was identified as Thomas Jennings, a recent parolee Investigators located a freshly-painted railing with a single fingerprint on it- it was a match to Jennings Jennings was the first person convicted in the US on fingerprint evidence  Minutiae Ridgeology The study of the uniqueness of friction ridge structures and their use for personal identification Minutiae Points where the ridge structure changes Points of Similarity When minutiae on two different fingerprints match The greater the number of points of similarity, the greater the evidentiary value  Minutiae There are several different types of minutiae used to categorize fingerprints: Bifurcations The point at which one friction ridge divides into two friction ridges Bridges A connecting friction ridge between parallel running ridges Eye/Enclosure/Lakes A single friction ridge that bifurcates and rejoins after short while and continues as a single friction Ending Ridge A single friction ridge that terminates within the friction ridge structure  Minutiae There are several different types of minutiae used to categorize fingerprints: Crossover A point where two ridges intersect Dots An isolated ridge whose length is also the same as its width Short Ridges Friction ridge of short length Hook A bifurcation with one short ridge branching off of a long ridge  Fingerprint Classification System The FBI’s classification system is based on the original Henry Classification System, which was created in 1901 They expanded it to deal with the increasing number of fingerprints in the system The first (primary) classification step is to divide the prints into the following sequence: R Index R ring L thumb L Middle L Little R Thumb R Middle R Little L Index L ring Each fingerprint is given points if it has a whorl pattern, based on the above sequence: 16 8 4 2 1 Each fingerprint is classified and the totals are added to make a fraction, which is the first classification step or primary classification as is exemplified below 16+ 0+ 0+ 0+ 1= 17 0+ 8+ 0+ 2+ 0= 10  Case Study: Richard Ramirez Starting in summer 1984, the residents of Los Angeles were in fear of a deranged killer who would burglarize then torture his victims He killed 13 people in random attacks On August 24, 1985, Richard Ramirez broke into the house of Bill Cairns and Inez Erickson He left in a stolen car which was located abandoned in Koreatown Ramirez had wiped the car down but left a single fingerprint on the rear-view mirror Police matched to known criminal Richard Ramirez, with a new AFIS system  IAFIS Integrated Automated Fingerprint Identification System (IAFIS) The national fingerprint database maintained by the FBI The FBI created IAFIS in 1999 and houses the fingerprints of over 100 million persons Fingerprints are voluntarily submitted to the FBI by local, state and federal law enforcement agencies For arrests, employment checks, visa applications The average response time through IAFIS is 27 minutes for criminal fingerprints and 72 minutes for others  How IAFIS Works IAFIS uses a computer to scan and digitally encode fingerprints Criminals and job seekers upload their fingerprints to an AFIS by using Livescan The machine records fingerprint patterns as a picture The machine allows fingerprints to be uploaded in seconds The computer software records the positioning of minutiae Especially ridge ending and bifurcations The orientation is recorded as a digital geometric pattern When a search is run, the computer provides the closest matches, which will be manually verified by a latent print examiner They will determine if there is actually a match  Career Spotlight: Latent Print Examiner A latent print examiner is a certified forensic technician who has taken specialized classes in latent print examination Latent print examiners detect, develop and identify latent prints left at crime scenes They then use IAFIS and state AFIS databases to find a match All matches must be manually checked The average salary in the United States is $50,871 The average salary in Texas is $69,757  Case Study: Dumpster Serial Killer In San Diego, California, there was a rash of prostitutes killed and dumped in dumpsters in a two-block radius Tara Simpson on August 29, 1985 Trina Carpenter on February 11, 1986 Joanne Sweets on May 9, 1986 Sophia Glover on August 15, 1986 At the dumpster of Joanne Sweets, investigators found fingerprints and palm prints on the plastic garbage bag containing her body They were matched to Bryan Maurice Jones He was convicted of murdering two of the women Bryan Maurice Jones