Crime scenes are known for leaving many clues behind. The evidence would be the body(s), the clothing and sometimes even the murder weapon. While this is a great way to solve a case, there is another type of evidence; trace evidence. Traces are small pieces of evidence found at a crime scene. There are many types of trace marks, including metal filings, plastic fragments, gunshot residue, glass fragments, feathers, food stains, building materials, lubricants, wood scrapings. nails, pollens and spores, cosmetics, chemicals, paper fibers and sawdust, human traces. and animal hair, plant and plant fibers, blood and other bodily fluids, asphalt or tar, vegetable fats and oils, dust and other airborne particles, insulation, textile fibers, soot, soil and mineral grains and residues explosives. Although these are the most frequently found items, they are not the only ones. The Trace Evidence unit is known for examining the widest variety of types of evidence and using the greatest range of analytical methods of any unit. materials are compared to known standards or samples to determine whether or not they share common characteristics. In this article, I will discuss the different types of traces and how crime scene investigators use them to solve cases and convict criminals. The traces were first discovered by Edmond Locard. Edmond Locard was born in 1877 and founded the Institute of Criminalistics of Lyon. He is also known for advancing the science of fingerprints. In 1910 he was allowed to open a small forensic laboratory at the Palais de Justice which he directed until 1951. There he worked on criminal identification methods, including poroscopy - the microscopic examination of fingerprints; analyzes of body fluids, hair and skin; and graphometrics or handwriting analysis. He is the originator of the theory that when two objects come into contact with each other, they leave behind some kind of material matter. This theory was later called Locard's exchange principle. The idea is that evidence can be used to associate objects, people or places with each other. » A person typically loses around 100 hairs per day. This hair can have probative value to show contact between two people. With an adequate capillary standard, a tracing chemist will be able to compare a medium of paper under a microscope...... furniture that can be locked. He will then use the small paint chips and metal as evidence and treat them the same way. A piece of evidence must be processed. Believe it or not, a victim's injuries are also evidence. The wound can allow investigators to match any marks that might have been made by the weapon and therefore allows them to determine at what angle and at what distance. , and how quickly the weapon was used. The last type of evidence I will talk about is documents. Everyone has different handwriting and different characteristics that make it unique. Computers are also unique in the way they type and print things. examine them and establish similarities in handwriting and computer forensics specialists can extract logs and other data from most devices. As you can see, there is no perfect crime. The smallest piece of hair, paint or whatever is left..