Impression Evidencestyle.visibilityppt_xppt_y


Types of fingerprints
There are three distinct types of fingerprints and they are:

1. Whorl 
2. Delta 
3. Loop style.visibility


Whorl fingerprint
A whorl pattern consists of almost concentric circles and two deltas. 
There are four types of whorls :
Plain whorl
Central pocket loop whorl 
Double loop whorl
Accidental whorl
Whorl patterns account for 25% of fingerprints


Loop fingerprint
   A loop pattern has only one delta.
 There are two types of loop patterns:               1. Ulnar loop               2. Radial loop
Loop patterns account for @ 70% of all fingerprints


Arch fingerprint
There are two types of arch patterns:                1. Plain arch,              2. Tented arch
Arch pattern account for 5% of all fingerprintsstyle.visibilityppt_xppt_y


Delta
The point on a ridge at or in front of and nearest the center of the divergence of the type lines.
The delta area is located as a triangular area where the ridges radiate outward in three directions


Minutiae
Minutiae refer to specific points in a fingerprint, these are the small details in a fingerprint that are most important for fingerprint recognition.
There are three major types of minutiae features: the ridge ending, the bifurcation, and the dot (also called short ridge). The ridge ending is, as indicated by the name, the spot where a ridge ends. A bifurcation is the spot where a ridge splits into two ridges. Spots are those fingerprint ridges that are significantly shorter than other ridges.


Techniques used to develop latent prints
Powders
Silver nitrate
Iodine
Fluorochromes 
Powders-Powders adhere to both water and fatty deposits. These are generally useful on newer prints only. 
Silver nitrate-Silver nitrate reacts with the chlorides in skin secretions to form silver chloride, a material which turns gray when exposed to light. It is not useful on items which have been exposed to water.
Iodine-Iodine fumes react with oils and fatty deposits to produce a temporary yellow-brown reaction product. 
Fluorochromes-Prints may be treated with special dyes called fluorochromes which easily are made to fluoresce and bond with the print deposits. They require an ultraviolet light source.



What is AFIS??
An automated fingerprint identification system (AFIS) is a system that uses biometric technology to store digital imagery of individual fingerprints for database comparison to produce a match. Fingerprints are considered a foolproof method for identification purposes because each fingerprint is unique. As digital technology progresses, fingerprinting is increasingly being used as a fraud prevention measure. This type of technological safeguard may be stored with personal data, such as passwords and personal identification numbers. Live scanning, which offers real-time fingerprint identification,  complements AFIS technology. 
AFIS is gaining popularity as a method used to identify individual user logins.



Impression evidence


Types of impression evidence
Footwear Impression Evidence-Shoe impressions or footprint impression evidence can be used to connect a culprit to the crime
Tire Impression Evidence-Tire impression evidence is used to point to the culprit's vehicle. Uniqueness by way of defects, skidding pattern, tire patching traces or uneven wear must first be established before the court dismisses the tire track evidence as class evidence.
Tool Mark Evidence-Tool Marks are defined in forensic science as impressions produced by an instrument on a surface. Crime scene investigators determine the nature of the tool by the indentation it leaves on the surface.
Bite Mark Evidence-A crime scene investigator must have a keen eye for detecting a bite mark on a dead body. Upon concluding that a bite mark has been impressed on the body, a forensic dentist will be called to measure and record the bite mark. This must be done immediately as bite marks loses its original impression over time. When the dentist confirms that it is a human bite, it will be swabbed for DNA.


Impression evidence used in reality
The serial killer, Ted Bundy, who confessed to 30 murders, was linked to two of his murders by bite mark evidence. When done right, the recording and analysis of a bite mark on a victim can provide a great deal of evidence in legal proceedings.


References
"Next Generation Identification (NGI)." FBI. FBI, 06 May 2016. Web. 06 Apr. 2017. <https://www.fbi.gov/services/cjis/fingerprints-and-other-biometrics/ngi>.
"Fingerprint Patterns." Fingerprint Patterns - Fingerprinting.com. N.p., n.d. Web. 06 Apr. 2017. <http://www.fingerprinting.com/fingerprint-patterns.php>.
T Martin Crime Scene Forensics, LLC. "Fingerprints." Fingerprints. N.p., n.d. Web. 06 Apr. 2017. <http://www.crimescene-forensics.com/Fingerprints.html>.