Different Types of Sensors and Their Applications

Latent fingerprints found at crime sights or else developed in the laboratory are categorized by examiners as patent, latent, or plastic impressions1. The word latent means hidden or unseen. Latent prints are undetectable until brought out with a physical, chemical and fuming process. The physical developer is a means to detect fingerprints on dry and wet, including paper articles, clay-based products and adhesive tapes. Ninhydrin is one of the most widely used chemical reagents for enhancement of latent finger print impressions on porous substrates. Nonporous surfaces do not absorb. These surfaces repel moisture and often appear polished. They include glass, metal, plastics, lacquered or painted wood, and rubber. Superglue (cyanoacrylate) fuming is the best example for such non-porous substrate analysis.

Latent fingerprint was excited with U.V light. This was done to see if the latent fingerprint shows fluorescence. Multiple photographs were taken with different settings, which included spectral filters, camera settings, and U.V light settings to find out if any fluorescence is displayed by the fingerprint residues and if so, to which extent it enhances the ridge characteristics of the fingerprint.

During the identification phase, the user puts the finger on the same sensor, generating a new fingerprint image or template called query print. Minutiae points are carried out from the query print, and the matcher module compares the set of query minutia with the stored minutia templates or image in the enrollment database to find the number of similar minutia points. Because of variations present in finger placement and pressure applied to the sensor, the minutia points take out from the template and query fingerprints must be lined up, or submitted before matching. After line up the fingerprints, the matcher decides the number of pairs of matching minutiae-two minutiae points that have similar location and directions. The system decides the user's identity by comparing the match score to a

Lee, H. (2001). Advances in Fingerprint Technology, Second Edition, 2nd Edition. Retrieved January 26, 2015, from Vital Source: http://online.vitalsource.com/books/9781420041347

samples of an individual’s fingerprint’s can be lifted from a crime scene. The breakthrough of

Fingerprints can be taken from a crime scene in various methods. Fingerprints are classified into three categories depending on the surface they are found. Fingerprints on soft surfaces are most likely to be three-dimensional plastic prints such as soap, wax, wet paint, fresh caulk, etc. (“A Simplified Guide To Fingerprint Analysis”, n.d). The fingerprints on hard surfaces are patent or latent prints including blood, dirt, ink, paint, etc. transferred from a finger or thumb to a surface (“A Simplified Guide To Fingerprint Analysis”, n.d). Patent prints can be collected using photography. The prints are photographed in high resolution with a forensic measurement scale for the image for reference. There are multiple methods for discovering and collecting latent prints. Alternate Light Source (ALS) use

A Fingerprint is a pattern of fine ridges and valleys (spaces between ridges) on the surface of a finger and fingerprint sensor makes a digitized image of it. The sensing resolution is 500ppi (pixel per inch; also known as 500dpi, i.e., dots per inch) in most cases, which is equivalent to 20 pixels in 1 millimeter. The obtained image size is typically in the range of between 300*300 and 512*512 pixels, which makes the area covering the fingerprint between 15 to 25 millimeters square.

FINGERPRINT EXPERIMENT2AbstractLatent print residue is a combination of many substances excreted from the body. Latent print residues may be left from natural sweat on the skin or from a contaminant such as motor oil, blood, ink, paint or some other form of dirt. They may exhibit only a small portion of the surface of a finger and may be smudged, distorted, overlapped by other prints from the same, or from different individuals, or all of these in combination. The factors that affect the quality or presenceof latent prints include the conditions involved between friction skin contact and the objects that are touched. Pre-transfer conditions describe the condition of the friction skin and the amount and type of residue on the skin; and are affected

In this phase a variable light source was used to excite the fingerprint residue. This was done to obtain fluorescence from the fingerprint residue. Various spectral filters and a range of camera settings accompanied with different light sources were tested to see if any fluorescence existed. The images were compared with each other to figure out if any sample shows florescence under any specific range of wavelengths. Since, we were unaware of the fact whether the fingerprints were contaminated during any experiment we used various wavelengths for the substances that might show fluorescence under different wavelengths. The level of detail in the images remained the same as the previous phase of research and

We live in a world today, in which technology moves at a very rapid pace. Many of these technological advances can be used to make our everyday lives easier and safer. One of these new technologies is Biometrics. Biometrics is the process of measuring a person’s physical properties. This would include measuring things like fingerprints, retinas, odor, vein structure on the back of the hand and many other things. Biometrics is a very important topic because it would create better security precautions for certain places that need to be secure. Biometrics will make our society safer by only allowing authorized people out of secure facilities and by keeping the unauthorized people out. Throughout the rest of this

The automated Fingerprint Identification System is also known as the AFIS within the law enforcement division (FBI, 2010). This system is an important element in the criminal justice system as some of its features encompass the storing of data, encoding, and fingerprint and facial comparison through graphics and other techniques. Law officials many centuries ago in the pursuit of positively identifying someone suspected of guilt have long used fingerprints techniques. Fingerprinting is also used in branches of our government, and in the Pentagon, the authentication method of fingerprints is used permit access to specified zones inside the building. Fingerprints are an effective and very precise method of identification purposes that does not pose

As one of the many fields of forensic science that can benefit from additional research, fingerprint identification is probably the most deserving. Within recent years, many print examiners have been questioned in both professional and social situations as to whether fingerprint evidence should be considered scientific. This questioning caused latent print examiners to realize the pressing need for various types of ongoing research on the subject of fingerprints.

“Fingerprint recognition is one of the divorce inference using the impressions made by the minute ridge formations or patterns found on the fingertips. No two people have exactly the same arrangement of the ridge patterns, and the remaining patterns of any one individual unchanged. Fingerprints infallible provide a means of personal identification. Other personal characteristics may change, but not fingerprints”. (1)

Every time somebody touches something, they leave behind a unique signature that forever links them to that object. This link is their fingerprints, which are unique to every person, for no two people have the same set, not even family members or identical twins. Palms and toes also leave prints behind, but these are far less commonly found during crime scene investigations. Therefore, fingerprints provide an identification process that is applicable to background checks, biometric security, mass disaster identification, and most importantly, crime scene investigations. Fingerprints are so differentiated because they are made up of distinct patterns of ridges and furrows on the fingers. The ridges are the “raised” portions of the prints, and the furrows are the “recessed” portions. This perceived uniqueness has led some people to falsely accept fingerprint analysis as absolute scientific fact. Although overall fingerprints are reliable, there are definitely situations where their accuracy can come into question.

Biometrics is used in many places and there is a bright future for them. Coca Cola has recently replaced time card system with hand scanning machines. Finger print scanners are being used in many states of the US. They have been used to trace social welfare fraud. An iris pattern identification system is being used in Cook County, Illinois to ensure that right people are released from jail. ATM machines have been installed with finger scanners to prevent theft and fraud in Indiana (Jain, 2005).