At the Crime Scene. FORENSIC SCIENCE - BURKS Crime Scene

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1 FORENSIC SCIENCE - BURKS Crime Scene At the Crime Scene Forensic science begins at the crime scene, which can provide useful information that must be carefully, systematically, scientifically, and legally collected. If the crime scene is not treated carefully, it can make vital information not only useless, but even deceptive, pointing an investigation in the wrong direction. Crime scene investigation is the meeting point of science, logic and law. "Processing a crime scene" is a long, tedious process that involves purposeful documentation of the conditions at the scene and the collection of any physical evidence that could possibly illuminate what happened and point to who did it. There is no typical crime scene, there is no typical body of evidence and there is no typical investigative approach. Investigators must treat the crime scene meticulously and accurately, taking great care to observe and collect all evidence that will be used for scientific analysis and its legal application. The main reason to carefully analyze the crime scene is to learn what happened and to gather evidence that can be used to identify and, legally, convict the people responsible. Oh how simple it would all have been had I been here before they came like a herd of buffalo and wallowed all over it. Sir Author Conan Doyle, Sherlock Holmes, 1892

2 FORENSIC SCIENCE - BURKS Crime Scene Crime Scene Search Arrive at the scene with the proper attitude and determine: 1. What has taken place? 2. Where is the scene? 3. What evidence do I need to document? 4. What evidence do I need to collect? 5. What processes must I perform? 6. What will I need for court? A major crime scene such as a homicide, a police involved shooting, or a buried body requires a massive amount of information to be gathered during the scene processing. This information must be readily available for you to complete a formal crime scene report after the processing has been completed. The investigation starts when you arrive at the scene and talk with the first responding patrol officer. You must learn as much as you can about the events that have taken place. Observations of the scene must be recorded as well as lighting, structure types, weather, police and fire units present, victim & suspect information, etc. This checklist should also be used to remind the investigator on seldom used processes or other possibilities while still at the scene. Information concerning the processes that you performed and the areas that were processed should also be recorded as well as the results. All of this information is necessary for you to write a complete and thorough report back at your office. The amount of processing required at a major crime scene is too extensive to remember, so a crime scene checklist should be utilized. The crime scene checklist should include but not be limited to the following: Weather Information Victim Information Evidence Lists Photography Log Rough Crime Scene Sketches Firearm Descriptions Entomology Vehicle Information The idea of a crime scene checklist is to record the information while at the scene so you can write an accurate report. REMEMBER - if it s not in your report, it never happened!

3 The Crime Scene First Officer Attending will have a number of duties to complete, the first of which is saving human life. Also, the FOA must deal with any emergencies as necessary. Any individuals already present at the scene, including witnesses and suspects, must be detained in case arrests are necessary. The FOA will informally interview any relevant persons in order to determine whether a crime has actually been committed and if any emergency aid is required, such as the summoning of paramedics. If first aid is given, the officer should take note of anything that is altered during lifesaving efforts, such as the movement of victims or objects. When scientific support personnel arrive at the scene, the FOA will share any relevant information he has gained with them. Crime Scene Preservation includes the barriers of a crime scene are established, ensuring that all vital pieces of evidence plus entrances and exits are included, and a physical barrier placed around the scene. This barrier may be crime scene tape, police officers standing guard, barricades or vehicles. This barrier essentially controls who enters the scene, aiming to exclude all non-essential personnel. A log is produced noting all individuals who do cross the barrier and the times at which they enter and exit. When documentation of the scene is complete, crime scene officers can then proceed to collect physical evidence from the scene. The nature of the evidence itself will determine the method of collection and how it is contained. It may be necessary to focus on the collection of certain evidence first, namely items that may be particularly fragile or valuable to the investigation. If a body is present at the scene, it will often be impossible to touch or move the victim until the necessary specialist has arrived at the scene, such as the pathologist. Before the body is transported to the mortuary, plastic bags are secured over the head, hands and feet to prevent the loss of trace evidence. As with recovery methods, the packaging of physical evidence is dependent on the nature of the evidence. All items collected should be packaged, stored and transported in such a way that prevents any change or damage from taking place between the time it is recovered and the time it is received by the laboratory. Small, drys item may be folded in paper, whereas wet items should be sealed in plastic bags and frozen, especially if they contain living material. Every item collected should be placed in a separate container to prevent damage through cross-contamination. Finally, all pieces of evidence should be labeled along with the location in which it was found, the crime it relates to, and the date and signature of all persons involved in its recovery.

4 C R I M E S C E N E S E A R C H During the systematic search for evidence, a leading investigator will often assign individuals to particular areas of the crime scene while overlooking the search for and collection of evidence. The way in which the scene is processed will often be determined by the nature of the crime. Indoor crime scenes will be quite simply searched on a room-by-room basis, whereas outdoor crime scenes may require a more detailed search pattern. There are a number of search patterns that may be followed: grid or zone or quadrant search: in this pattern the scene is divided into smaller, portions which are searched individually. Parallel or line search: officers form a line and move forward side-by-side, covering the entire scene together. In spiral search: The investigator begins at the epicenter of the room and moves outwards in a spiral pattern. Or alternatively the investigator starts at the edge of the scene and spirals into the center.

5 Crime Scene Sketch Sketching is a permanent record of the size and distance relationship of the crime scene and the physical evidence within it. The sketch serves to clarify the special information present within the photo-graphs and video documentation, because the other methods do not allow the viewer to easily gauge distances and dimensions. A sketch is the most simplistic manner in which to present crime scene layouts and measurements. Often photographer / camera positions may be noted within a sketch also. Two types of sketches are produced with regards to crime scene documentation: rough sketches, and final/finished sketches. Rough sketches are developed while on-scene, typically during the crime scene assessment/preliminary scene evaluation phase to assist with development of a strategic plan for processing. The sketch is not done to scale, can be drawn with any implement (crayon, chalk, pencil, pen, etc.), and is very rough artistically. A final sketch is a finished rendition of the rough sketch. They are usually prepared for courtroom presentation and often will not show all measurements and distances originally recorded on the rough sketch. Crime Scene Sketching Scene Sketch Compass Orientation North Not to Scale Four different crime scene p e r s p e c t i v e s c a n b e represented within a sketch: (a) the bird s eye or overhead view, (b) the exploded or side view, and (c) the threed i m e n s i o n a l ( 3 D ) v i e w. Sometimes personnel choose to incorporate several perspectives within a sketch (e.g., using both elevation and overhead sketches to draw an exploded or cross-sectional view of a scene). Legend Object # Fixed Point Fixed Point

6 Photography Crime scene photography, also called forensic photography, has been around almost as long as the camera itself. Criminologists quickly realized that such technology could freeze time -- creating a supposedly incontestable record of a crime scene, a piece of evidence or even a body. The 19th century French photographer Alphonse Bertillon was the first to approach a crime scene with the systematic methods of an investigator. He'd capture images at various distances and take both ground level and overhead shots. Today, forensic photographs are essential for investigating and prosecuting a crime. This is because most evidence is transitory: fingerprints must be lifted; bodies must be taken away and examined; and homes or businesses must be returned to their normal state. Photographs help preserve not only the most fleeting evidence -- like the shape of a blood stain that will soon be mopped up -- but also the placement of items in a room and the relation of evidence to other objects. Such images can prove vital to investigators long after the crime scene is gone. There are three classifications of forensic photos -- overviews, midrange and close-ups. If the crime took place inside, overviews include photos of the outside of the building, its entrances and exits as well as images that place the building in relation to its surroundings. Overviews also include images of all rooms, taken from overhead and from each corner. The forensic photographer then hones in on key pieces of evidence and captures images of them in the context. These mid-range photos might picture a piece of evidence, like a knife, but at enough of a distance to show its relation to furniture, a blood stain or the rest of the room. Mid-range images establish the distance of object from surrounding objects. Finally, the photographer thoroughly documents evidence with close-up images. Close-ups include identifying marks like scars on a corpse or serial numbers on a bloodied piece of electronic equipment. A photographer will often include a ruler in the shot to establish scale but always takes a duplicate image without the measuring device. If the measuring instrument is not removed, the defense could claim the device covered something important.