Case Study in Fingerprint
Category : Science
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Case Study in Fingerprint
We tend to leave a fingerprint behind in almost every time we touch something. This is because our hands are covered with sweat pores that are often mixed with other body oils which stick to the surface of the object we touched. While fingerprinting has been widely used for identification purposes, it gained its usefulness in the forensic science as a means of identification to help solve crimes.
Over a century past when police agencies found a powerful means in skirmishing crime. The call for extremely accurate means of identification was found by crime fighters in the use of fingerprinting technique. Cartographic characteristics of a person as another means of identification may change but not in fingerprinting.
Fingerprinting was not used and accepted widely for criminal identification until the 1900s even though awareness of its reliability was developed on the unique set of ridges on the fingers and hands.
The technique of fingerprinting was used to identify an unknown victim, witness, or suspect, to verify records, and most importantly, serves as links and matches between a suspect and a crime. Leads can still be developed even without direct suspect through prints. Additionally, prints can validate or disprove a statement of a victim, witness, or suspect by locating their prints where they said they were during the crime.
On May 16, 2005, a bank in Taiwan was found to be robbed with no traces of force entry. It was then Monday, 10:30am when the bank employees suspected that there was something wrong with the vault. They could not open it. It seems like the vault combination has been changed.
Normally, the bank is off during Saturdays and Sundays. Suspecting of a possible burglary inside the vault, employees then called the police. The police then came in a couple of minutes. As expected, the police had a hard time on how to open the vault since most bank vaults are thick, pure metal. Breaking the concrete was an alternative that worked.
Bank employees, along with police inspectors, was shocked in awe after seeing that the vault is empty. Boxes from the cabinet was scattered leaving nothing in it. The robbery was done cleanly, leaving no physical evidences behind. All what’s being left is a huge whole in the ceiling of the vault. No wonder there has been any sign of force entry in the doorways.
Police restricted employees from touching anything inside the vault. It seems clear to them that the crime happened during the weekend. Inspectors then collected evidences and wait for Lab Technicians to the crime scene since they’re the first hope in solving the case – fingerprinting.
2. Literature Review
Fingerprints offer an infallible means of personal identification. That is the essential explanation for their having supplanted other methods of establishing the identities of criminals reluctant to admit previous arrests.
The science of fingerprint Identification stands out among all other forensic sciences for many reasons, including the following:
· Has served all governments worldwide during the past 100 years to provide accurate identification of criminals. No two fingerprints have ever been found alike in many billions of human and automated computer comparisons. Fingerprints are the very basis for criminal history foundation at every police agency.
· Established the first forensic professional organization, the International Association for Identification (IAI), in 1915.
· Established the first professional certification program for forensic scientists, the IAI's Certified Latent Print Examiner program (in 1977), issuing certification to those meeting stringent criteria and revoking certification for serious errors such as erroneous identifications.
· Remains the most commonly used forensic evidence worldwide - in most jurisdictions fingerprint examination cases match or outnumber all other forensic examination casework combined.
· Continues to expand as the premier method for identifying persons, with tens of thousands of persons added to fingerprint repositories daily in America alone - far outdistancing similar databases in growth.
· Outperforms DNA and all other human identification systems to identify more murderers, rapists and other serious offenders (fingerprints solve at least ten times more unknown suspect cases than DNA in many jurisdictions).
Other visible human characteristics change - fingerprints do not. In earlier civilizations, branding and even maiming were used to mark the criminal for what he was. The thief was deprived of the hand which committed the thievery. The Romans employed the tattoo needle to identify and prevent desertion of mercenary soldiers.
History of Fingerprints
Before the mid-1800s, law enforcement officers with extraordinary visual memories, so-called "camera eyes," identified old offenders by sight. Photography lessened the burden on memory but was not the answer to the criminal identification problem. Personal appearances change.
Around 1870, a French anthropologist devised a system to measure and record the dimensions of certain bony parts of the body. These measurements were reduced to a formula which, theoretically, would apply only to one person and would not change during his/her adult life.
This Bertillon System, named after its inventor, Alphonse Bertillon, was generally accepted for thirty years. But it never recovered from the events of 1903, when a man named Will West was sentenced to the U.S. Penitentiary at Leavenworth, Kansas. You see, there was already a prisoner at the penitentiary at the time, whose Bertillon measurements were nearly the same, and his name was William West.
Upon investigation, there were indeed two men who looked exactly alike, but were allegedly not related. Their names were Will and William West respectively. Their Bertillon measurements were close enough to identify them as the same person. However, a fingerprint comparison quickly and correctly identified them as two different people. (Per prison records discovered later, the West men were apparently identical twin brothers and each had a record of correspondence with the same immediate family relatives.)
In 1686 and 1823, two professors of anatomy noted and discussed ridges, spirals, loops and even patterns in fingerprints. Unfortunately, they failed to mention the value of fingerprinting for personal identification.
But during the 1856, , Chief Magistrate of the Hooghly district in Jungipoor, India, first used fingerprinting on native contracts. It was somewhat a mere breakthrough towards personal identification. The idea was merely to frighten out of all thought of disclaiming his signature that made the native impressed and Herschel made it a habit of palm printing since then.
On the 1870’s, a British doctor of Tsukiji Hospital in Tokyo, Japan, not only recognized the importance of fingerprints as a means of identification, but developed a method of classification. then discussed fingerprints as a way of personal identification and much more the use of printers ink in obtaining such fingerprints.
From then on, fingerprinting spread to places and later then used by most countries in the field of criminology. It is now widely used in criminal records due to its reliability in solving cases. In addition, fingerprinting can detect previously convicted person and of proving their guilt.
Fingerprinting served to the purpose of providing previous conviction against an accused person denying a crime and providing evidence of guilt of an accused person in a specific case.
In 2005, The FBI's Integrated AFIS (IAFIS) in Clarksburg, WV has more than 49 million individual computerized fingerprint records for known criminals. Old paper fingerprint cards for the civil files are still manually maintained in a warehouse facility (rented shopping center space) in Fairmont, WV, though most enlisted military service member fingerprint cards received after 1990, and all military-related fingerprint cards received after 19 May 2000, have now been computerized and can be searched internally by the FBI. In some future build of IAFIS, the FBI may make such civil file AFIS searches available to other federal crime laboratories.
All US states and larger cities have their own AFIS databases, each with a subset of fingerprint records that is not stored in any other database. Thus, law enforcement fingerprint interface standards are very important to enable sharing records and mutual searches for identifying criminals .
· The patterns of ridges on our finger pads are unique: no two individuals—even identical twins—have fingerprints that are exactly alike.
· We leave impressions—or prints—of these patterns on everything we touch with any pressure.
· Injuries such as burns or scrapes will not change the ridge structure: when new skin grows in, the same pattern will come back.
· Dactyloscopy is the practice of using fingerprints to identify someone
- Fingerprints can be classified by pattern types, by the size of those patterns, and by the position of the patterns on the finger.
There are three methods you can use for taking prints:
1. Not recommended: actual rubber-stamp ink pads—too much damage to clothing and surroundings likely
2. Easiest and cheapest: rubbing pencil all over a small area of paper or index card to make an “ink” pad, pressing fingers onto the penciled area, lifting prints from fingers with transparent tape, and sticking tape to white index cards for reading
3. High-tech, neat, and not too expensive: using purchased Identiprint materials.
Identiprint is a commercial system used by retail merchants to put customers’ thumbprints on the backs of their checks without making an inky mess. Special “ink” pads and self-stick labels take a dark, clear print without leaving any visible residue on the thumb. I found supplies by searching the Web for “Identiprint.” A dealer took a telephone order for a roll of 500 labels and a dozen pads, at a cost of less than $35 in 10/97, which I received some ten days later. You may also ask a high-volume retail merchant near you to donate a small supply for classroom use. Experimentation has shown us, however, that the pencil method is actually easier to use—if harder to read
3. Analysis to the circumstances of the crime and the collection of evidence
Lab Technicians, as a standard operating procedure, would look for any possible articles or things that might have been handled by the robbers. A quick thought from police inspectors that the robbery involved a number of robbers.
In this case, there are a lot of things that the robbers moved or handled in view of the suspected numbers of robbers that there were more than 2 robbers perceived. Additionally, drawers in the cabinet are apparently touched since most of it is scattered on the floor.
Technicians should also have to look on some articles or things that might be left within the possible entry of the robbers. It could be along the perceived point of entry to the probable path that robbers took.
Investigators collected articles which may have been handled by suspects whose characteristics is desired to establish. In this case, inspectors and technicians saved the cabinets and drawers. Moreover, Investigators found some articles that were seemingly not from the bank – several tools left. These articles recovered can be a strong and solid source for the identification of fingerprints on the said items.
4. Manner of evidence collection
Step 1: After the entry into the vault, the police contained and limit employees and other outsiders from touching or contact with things inside the vault. This is a standard operating procedure to preserve the reliability of evidences in the crime scene.
The technicians and investigators wore gloves and took out probable items alleged to be handled or moved by burglars that might be taken samples for fingerprinting. They carefully held cabinets and the left items in order not to destroy any available fingerprints on the handler which is perceived to belong to the robbers.
Step 2: The recovered items from the crime scene were placed into a sealed plastic bag. Cabinets and drawers as well were handled over separately in a container.
Step 3: More importantly, investigators and technicians in charge of the crime scene investigation noted down the date and time of recovery of the evidences. They labeled the items from where it has been found, the name of the investigator who found it, and what the item was and its description briefly. Finally, the collector’s signature was affixed on the bag.
The case was:
Date of collection: May 16, 2005
Time of Collection: 10:35am
Cabinets and Drawers – inside the vault
Items and tools from the robbers – a meter away from the bank
Who collected the items:
What were the items: Cabinets, Drawers, and Tools
Description: Tools – screwdriver and wires. These tools were strongly believed to be used in the blasting the vault’s ceiling.
Step 4: All the evidences gathered and recovered from the crime scene were sent to the Lab to be studied and recover fingerprints on the items if there were any.
5. Laboratory Findings Reliability
Evidences presented to the Lab were in the “fresh state” which obviously can be easily said because of the time frame of the robbery. With this fact, Fingerprint Laboratory wouldn’t have a hard time taking the fingerprints left on the presented items.
Within the two ways of detecting fingerprints which of course depends on the surface that the prints were left, the appropriate and easier way will be the Mechanical Method. Here are some of the uses of such method:
A. Gray and Black powders are adequate for most latent work. Fingerprints experts will select the powder affords the best color contrast with surface being dusted. Usually, they will use the camel’s hair or fiberglass brushes apply the powder to objects. If the surface is light in color, the dark-colored powder is used such as charcoal and graphite. In contrast, the object is dark in color; the light-colored powder is applied on the surface. “Grey powder” is the commonly used in this situation (Brood, A. J. Jr. 1972).
B. Magnetic sensitive powder is a good way to develop the prints since it has less chance to destroy the prints. It is spread over a surface with magnet in form of magna brush. The black and gray colored powders are applying on the furnished leather and rough plastic.
C. Fluorescent powder will be fluoresced under ultraviolet light. It is also a good tool to be used to detect the fingerprints because of avoid having color of surface obscure the prints ( 2001).
Identification of Fingerprints
Fingerprints speak for themselves, no fears, no hopes, no will of prisoner to falsify or to exaggerate could produce or create a resemblance of her fingerprints or change them in one line, therefore, no danger or error being committed or untruth told. No two fingerprints can be alike that the prosecution may be relieved of the burden of proving this contention and that the burden of proof to the contrary rests on the accused.
(1) Proof of identity of victim: fingerprints are admissible to prove the identity of victim.
(2) Purpose of identifying a defendant and then, connecting the person with the scene of crime.
(3) Proof of innocence: a defendant introduces evidence in his/her own behalf, tending to show that certain fingerprints are not his/her own. If he/she proves to the satisfaction of court that no other fingerprints than those he/she offers in evidence were on the object.
Due to the above three reasons, identification of fingerprints are very important.
The mechanical way is good for developing most of the latent prints on the smooth surface; however, the powder cannot be used on the documents. The chemicals can be overcome this limitation. The latent impressions are made visible by chemical reaction. The substance used may be a vapor, iodine or liquid (solution of silver nitrate). The substance is to change the transparent and invisible sweaty deposit into something which is opaque and which will be of a color contrasting with that of the surface on which it occurs.
Reliability of fingerprint examination is supported by the theories of biological uniqueness and permanence, probability modeling, and empirical data gained through over one hundred years of operational experience. Reliability means reproducibility in lay language. Scientific explanation which means a consistence of measure will produce the same results if employed again in the same circumstance ( 2002).
In 1880, published the first comment in scientific journal, Nature, on the use of fingerprint to solve crime. The reliability of fingerprint is high because of at any point of history, there is no two prints are identical. The World population is about 6 billion in 2005, and, there is only 1 print in 64 billions might be similar. The ridge patterns on the fingers which appear three or four months before birth and it never change throughout life, even damaged by strong acidic solution. If there is no damage of dermis layer of tissue, ridge will not change and re-appear again after recovery. However, in rare occasions, fingerprint identification error occurs.
False negative: someone whose fingerprints were left on scene if falsely exonerated.
False positive: innocent person appears to be guilty.
Reliability is insured by proper training, experiences and ability. There are 4 steps to keep the reliability high which is so called, ACE-V (1999).
1st step: Analysis; determine the flow of ridge and mark the prominent features on fingerprints.
2nd step: Comparison; to individualize the fingerprints and possibly match a print with the known print and compare them.
3rd step: Evaluation; to make sure that the analysis and comparison is done properly and correctly.
4th step: Verification; let other fingerprint expert to verify the findings.
The last step is very important because the risk of misinterpretation of fingerprints can be minimized if having a peer to review the findings.
There are two types of error that can be made, Practitioner error and error of science.
Error rate of science of fingerprint is zero. Since science allows for only one correct answer, unless the fingerprint examiner makes a mistake, it will be the correct answer. Fingerprint examiners either give all or nothing judgments ( 2001).
Practitioner error can be separated from the error of science. There is no way to know this error since it does not have detailed knowledge of casework result from all departments. For instance, Pilot error causing an aeroplane crash. This accident does not mean that the scientific principle explain flights are flawed. The other example is that mathematician gives the incorrect answer to a problem. It does not invalidate the science of mathematics. Thus, the wrong interpretation of fingerprint does not mean that there is an error of fingerprint.
Error rate is difficult to calculate because fingerprint reliability is dependent on the personnel, training and method used. A research has been done for determining the error rate in mock crime scene. 2 out of 3861 of comparison from mock crime scene were incorrect. The error rate of it is 0.034%. However, in reality, the error rate is up to 0.8% on average ( 2005). The reliability of fingerprinting was established about 100 years ago when fingerprints were first used as evidence in a criminal matter.
6. History of the Case
The robbery in the bank of Taiwan wasn’t the first time that happened in the same year. There were at least a number of bank robberies even with the onset of the first quarter of 2005.
Investigators, like , have developed probable suspects to the robbery. Most of the investigators, even working separately, have a common suspect – fugitives. Robberies and other criminal acts were mostly fugitives involved. In this focused case, Mr. Lee was looking on a possibility of local and/or foreign fugitives.
The case can be traced back to the headlined news about foreign fugitives believed to be hiding in Asia, particularly in the East. There were a number of names appeared on the Taiwan’s news and current affairs that year.
7. Techniques available at the time
Fingerprinting seemed to be the most reliable way of solving the case after investigators failed to collect witnesses and strong evidences that would directly point out a suspect in the instant.
Within the 10-meter radius from the bank, investigators watchfully gathered additional evidences from the crime scene. Traces of prints from boots were also of use but not as solid a result as that of the on-going Laboratory fingerprinting. Nevertheless, it would greatly help to the development of the investigation.
Some experienced and highly skilled crime scene investigators like had built up a 3D reenactment of the crime and came up with possible 3-5 suspects. The invented reenactment was based on the appearance of the vault after the robbery. Furthermore, to bore a whole by the ceiling cannot be only done by one or two persons only. And to take note that the alarm was properly deactivated would just simply explain that the heist was almost perfectly plan in time.
The technique of fingerprinting and relying on the results proved to be a firm foundation for the systematic solving of the case. Through the years, this technique of solving a no-physical evidence crime has yet been discouraged by most criminal departments.
8. Analyzing the Samples
A. went to the crime scene with a group policemen and investigators. He walked around the scene in order to look for all possible evidences that would be relevant for the solution of the case. Immediate in charge of the investigation gave information to that there were about 3-5 persons responsible for the robbery. , with his gloves on, then collected the possible evidences that suspects take a hold on things for the presentation to the Lab for fingerprinting analysis.
B. In the Lab, tried to obtain all the fingerprints that were on every item presented from the crime scene. With the gloves on, then tried to absorb fingerprints using the mechanical method as what is appropriate for the case. The “grey” powder was then used because of its lightness color powder. Fingerprints collected by lifting with an adhesive tape and prints preserved by leaving it untouched on the surface and recorded by photographic means. After making the lift onto the tape it is pressed onto opaque lift cards having a very smooth surface. The opaque cards are usually black or white and are chosen appropriately to contrast with the powder used.
Step 1: Dusting
Human’s fingers have a coating of perspiration and oil. Also each finger has a specific ridge pattern. When fingers touch any surfaces, the friction releases the oil from between the ridges. When applying the “gray” powder to the surface, the powder sticks to the oil and bring out the ridge pattern.
Step 2: Brushing
The camel’s hair brush was used to bring out the ridge pattern found on the handle of the cabinet and drawer. Shaking the brush before using would be a practical to make the brush more fluffy and for a smoother brushing.
Brushing was done slightly, swinging back and forth on the surface of the item following the direction of the ridge as prints eventually appeared.
Step 3: Lifting
Soon as prints were developed on the surface, adhesive materials like cellophane tape, rubber lifter, and hinged lifter were used in lifting it up. For the best result, a high quality clear transparent tape was used in lifting up the obtained prints. The tape was unrolled a little at a time and folded over a bit to use a tab for handling.
Air bubbles under the tape would destroy the value of prints so the tape was lightly rubbed over the prints. After the tape was firmly in place, the print was lifted by pulling the roll gently and evenly away from the surface.
Step 4: Photographing
It would be now the obtaining a copy of the prints through photographing after successfully lifting the fingerprints.
Step 5: Labeling
The lifted prints were labeled accordingly. It was marked what the item was, who handled it, the date of developing the fingerprints and the attachment of investigator’s signature on the cards. It was then sealed in separated bags and stored in the Lab’s cabinet.
Matching the obtained fingerprints to suspects
The Lab findings appeared to have four different fingerprints on the cabinet surface and drawer, and found another one on the tool. It matched to the local police records the two fingerprints. Suspects were then invited by the police and took samples of their fingerprints. Samples were then immediately sent to the Lab for the comparison of the rolled fingerprints to that of the suspects.
Process of getting the rolled fingerprints:
In the police precinct, a policeman obtained the first (A) suspect’s fingerprint by pressing its finger into the black ink tape. The policeman then rolled suspect A’s fingers and thumbs from nail edge to nail edge. The prints showed the entire friction surface of fingers and thumbs from the tip to one quarter inch below the first joint. The policeman successfully collected the ten fingerprints of the two suspects. It was also the policeman that made a photographic record of the fingerprints of the suspects.
Analysis of the suspects’ fingerprints
With a computer, fingerprints from the suspects were analyzed manually after obtaining it from the police. To properly compare the fingerprints, it was enlarged to A-4 size big and scanned them in the transparency. Initially, the ridge characteristics were found to have prominent patterns in item A (cabinet). The same patterns in suspect A’s fingerprint of right thumb were found to match that from the collected evidence fingerprint.
Doing the same procedure, it was now then the comparison of the suspect B’s fingerprint. It was found to have 12 comparison points from both prints. After comparing the fingerprints physically, the findings were verified in the computer.
used a digital camera to take a photo of the two fingerprints and zoomed them up to the visible size for clear comparison in the computer. It was then verified again by a fingerprint expert.
Comparing the findings
It was the right thumb of the suspect A that matched that of the one from the cabinet surface. On the other hand, item B (drawer) was compared to that of the suspect’s fingerprints and the prints developed from the evidences.
Comparing the Item A with that of the suspects’, it clearly showed that the right thumb prints on the cabinet surface matched from one the suspects which was suspect A. A solid and reliable result that 10 comparison points between the two compared fingerprints, matched apparently.
The prominent ridge characteristics in item A’s fingerprint were (1) bifurcation, (2) enclosure, (3) bifurcation, (4) short ridge, (5) enclosure, (6) ridge ending, (7) bifurcation, (8) bifurcation, (9) island and (10) short ridge. Suspect A also has the same ridge pattern.
In comparing Item B with the suspects, it was found the fingerprint of Suspect B matched the fingerprint on the handler of Item B. The ridge patterns of Item B were (1) ridge ending, (2) short ridge, (3) short ridge, (4) ridge ending, (5) ridge ending, (6) short ridge, (7) bifurcation, (8) bifurcation, (9) island, (10) bifurcation and (11) bifurcation.
In search for the other suspects
There were actually 3-5 suspects perceived but there were only two who were detained. The Lab results gathered other three fingerprints that didn’t matched any local police criminal records.
There then came the investigators’ suspicions of having the involvement of foreign fugitives. With the technology of Taiwan, it is never impossible for the utilization of power tools used for the bank heist. But as the results from the Lab proved to be only two local Taiwanese were involved, a call for international criminal connection was then required.
International fugitives’ involvement was rampant in many countries worldwide. In Taiwan, with the cooperation of international fugitive watch, crimes such as the bank robbery and other crimes involving the foreign fugitives’ participation were significantly minimized.
In the case of the bank robbery, the international cooperation of Taiwan produced fives names from international criminal list. Three of which were positively identified through their previous records from their own country.
With the provision of such personal information of the foreign suspects from their country, fingerprint samples taken from the Lab other than those from the two locals convicted earlier, unsurprisingly matched that of the international fugitives.
In the later couple of months, news had been heard about the capture of the said fugitives. Thanks to the power of fingerprinting, had these criminals been left roaming anywhere else and would cause another crime or disaster.
From the findings gathered from the suspects and the known fingerprints, items A and B evidently matched the print of suspects A and B, respectively. As a matter of fact, there is no two fingerprints alike and thus when the ridge characteristics of two fingerprints are in identical sequence, it will be in no doubt, comes from the same person.
Just recently, forensic science has been questioned as to the reliability of fingerprinting by many courtrooms. The matter points out two possibilities that would prove fingerprinting technique unreliable. First, the accuracy of making identification from dusted or latent prints from smudged, distorted or fragmentary that has never been scientifically tested. Secondly, the query aimed at the certainty of fingerprint examiners about their work that as human as they are, examiners do make mistakes. Obviously, these matters were raised by the defense lawyers in defending their client.
In the case of focus in this paper, suspects A and B were immediately detained for such result. And with the international cooperation, the three other foreign fugitives were captured adding the case into their criminal record. This would just show that the technology of fingerprinting is one of the best reliable ways to show individual’s involvement to a crime so far.
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