Partner Article

Identifying And Collecting Physical Evidence

There are many differents things involved in the identification and collection evidence. In order to do these things you have to know what things like what physical evidence is, what impressions are, different types of evidence you could find and how to use it and knowing what forensic science is and the different types is important too. Also you need to know the proper labelling technique. In order to prosecute someone you have to be able to prove they were at the scene of the crime when the offence was commited.

The collection, analysis and preservation of physical evidence is crucial part of police work. Physical Evidence can be defined as any object, impression, or body element that can be used to prove or disprove facts that relate to the offence. This type of evidence is very important because it often has a greater impact in court than evidence that is obtained through a witness’s statement. The different ways used to examine the evidence is called forensic science. Forensic science is the application of biochemical and other scientific techniques, also the study of physical evidence .

There are many subfields of Forensic Science including Forensic Anthropology, Forensic Biology, Forensic Chemistry, Forensic Computer Science, Forensic Psychology, etc. Forensic scientists do not collect evidence, interrogate suspects, or make arrests. Their job is to examine and analyze the physical evidence collected at a crime scene. The scientists spend most of their time working in a laboratory but also spend a fair amount of time giving expert testimonies and inquests. The most well known type of forensic scientist is the medical doctor who performs the autopsies.

They are the ones who determine the time and cause of death. Others specialize in things like firearms where they are able to analyze bullet fragments or gunshot residue to identify the type of gun used to commit the crime or in entomology they can determine a victim’s time of death and location of the murder by the types of bugs on the body and their life stage. There are two different types of impressions, class characteristics and individual characteristics. Class characteristics are the general features of an object such as size, model, make, and type.

The second is individual characteristics which are just more specific features of an object. Impressions are patterns and marks found on many surfaces caused by different objects such as things like fingers, shoes, gloves, tires or tools. The impression is recorded by photography, scanning it, or taking a mould of if. Next they try to match the impression with the object that made it. Fingerprints are one example of evidence normally found at a crime scene. Fingerprints are patterned marks left on surfaces from ones fingertip.

Prints can also be taken from a persons hand, feet, or toes but, fingerprints are the easiest to work with. A persons fingerprint never changes, nor do they share that print with any other human being so it is the best type of impression to use to identify the offender. There are two different types of fingerprints one is visible and the other is latent. Visible fingerprints are prints formed when the finger is coated in blood or something that people can easily see. Latent fingerprints are formed by natural oils in the fingertip, therefore invisible to the naked eye.

Some people try to hide their prints by wearing gloves but what they don’t realize is that police can use glove impressions to identify a suspect in almost the same way they do with normal fingerprints. Shoe prints and tire tracks are another way to identify a suspect. By seeing shoe prints at the crime scene the police can determine the suspects approximate height and weight, if they were running or walking, also whether or not the person had any injuries or got any at the scene of the crime. Most time they look for a tleast four prints to help them determine those things.

Tire tracks can help the police determine the type of tires, the type of car and the way the car was travelling. Most crimes include the transfer of bodily fluids or substances such as things like blood, skin, hair, mucus and semen. The police can use any of the substances found on or around the victim for DNA testing and other laboratory tests to match the elements to a particular suspect. Clothing fibers is another one that can be easily transferred from an offender to the victim during the crime. Police can match the fibres with those found in a victims clothes, homes, or cars.

DNA The labelling of the evidence is the duty of a scenes of crime officer, done so it can easily be found at a different time. Evidence collected at the scene is all placed in a “evidence package” and tagged. On the tag and the outside of the package the following are provided; description of item, police case number, date when it was collected, location in which it was collected, brand name if any, serial number or clothing information, the name and badge number of the officer who collected the evidence, and the destination that the item is being sent for analysis or storage.

Also by labelling it properly police are assured the evidence has not been tampered with or contaminated. The officers will also establish a chain of custody for the evidence. A chain of custody document is a witnessed, written record of all the people who had contact or control over the evidence. When it is produced in court it must show who had contact with the evidence, the date and time that the evidence had been handled, the circumstances in which the the evidence was touched, and what changes, if any, were made to the evidence.

In September 2009 there were sperate home invasions in the area of Tweed Ontario, two women were bound to chairs, photographed and sexually assualted. Police investigate but come up with nothing at the time. Then around November 25th a cpl. Marie-France Comeau, a flight attendant at the Canadian Forces Base Trenton, is found dead in her home in Brighton Ontario. Then on January 28th, 2010 a woman named Jessica Lloyd is last seen alive and reported missing the next day. About a week later the OPP and Belleville police set up a traffic stop on a highway near Belleville and questioned drivers for 11 hours.

Colonel Russell Williams, 46, comes to the attention of the police during his stop because of his vehicle and distinctive tire tracks. A neighbouring witness had seen an SUV outside of Jessica Lloyds house the night before her disappearance. Three days after that Williams was called to the Ottawa police station for questioning with the Ontario Provincial Police. Williams didn’t talk much at first a just played it cool as the interrogator discussed information, mentioning not just the murders near his cottage/second home but also the two sexual assualts near his actual home in Tweed. He still stayed casual and denied things as the man talked.

What he didn’t know is that they were already onto him. After some questioning they asked to take a print of his boot, revealing the fact that his boots were an exact match to those at Jessica Lloyds. Also male DNA had been found on Marie Comeau’s body that would later be matched to Russell. The interrogator acted friendly and tried to get Russell to open up more and after about ten hours he got what he wanted. Russell confessed to the murders and explained what happened and where Jessica’s body was. He also told them they would find evidence and photos of the attacks in his Ottawa home.

While that was going on police investigated both of his homes and found boxes of underwear, bra’s and pictures from different womens houses that he broke into. Russell was arrested that day then went to court not long after. Russell Williams pleaded guilty to 88 charges including first-degree murder, sexual assault, and breaking and entering. He was sentenced to 25 years in prison with no chance of parole.

Works Cited: http://lawaspect.com/

This was posted in Bdaily's Members' News section by Jacob Mcmillen .