Finger Print Analysis
Along with DNA, fingerprints are a main identifier for who we are. We give them when applying for some jobs, they give access to our criminal records, and they can be used to identify who we are in death. Even more importantly, when it comes to crime, fingerprints can help identify individuals who may have been at the crime scene. Fingerprints can be found on almost anything that a criminal may have touched at a crime scene. This can include doorknobs, pens, mugs, glass panes, and many other surfaces. In order to identify and analyze fingerprints, the crime scene investigators and forensic scientists will use a specific and specialized process.
Collecting the Prints
The fingerprints are collected using photography of dusting. When a set of fingerprints is found on a smooth, non-porous surface, they will be dusted to make them visible, then photographed in high resolution. To capture the fingerprints, investigators will place a piece of tape over them and pull it off, and the tape will subsequently be placed on a special card to protect it. Images that cannot be dusted will have a photo taken with a measuring device next to them using a high-resolution camera. Dyes and other chemicals, as well as other analyst methods can be used to identify these prints.
Law enforcement analyzes fingerprints in a crime laboratory. The examiner will look at the collected prints under a microscope and match them against prints in a database. To do this, they can use small parts of a print or a variety of print captures. The analysis may also uncover physical features such as recurves, deltas, creases and scars that can indicate where to begin the comparison. The analyst compares minutiae characteristics and locations to determine if they match. Known prints are often collected from persons of interest, victims, others present at the scene or through a search of one or more fingerprint databases such as the FBI’s Integrated Automated Fingerprint Identification System. The evaluation of prints will go through more than one examiner to verify accuracy.
Fingerprint analysis can take time if the prints are found to be conclusive. This process is quite painstaking for examiners, as they must identify every detail possible to match the print, find the person the match belongs to, find out if they are of interest, and have the prints verified. However, this helps fine-tune the process of finding out what happened and who was involved at a crime scene into a more effective endeavor.