<CHAP NUM="2" ID="CH.00.002">chapter 2
<FM><TTL>Introduction
</TTL><KTSET><TTL>Key Terms</TTL>
<KT>buccal swab</KT>
<KT>chain of custody</KT>
<KT>finished sketch</KT>
<KT>physical evidence</KT>
<KT>rough sketch</KT>
<KT>standard/reference sample</KT>
<KT>substrate control</KT>
</KTSET><OBJSET><TTL>Learning Objectives</TTL>
<P>After studying this chapter you should be able to:</P>
<<OBJ><P><INST> </INST>Define physical evidence</P></OBJ>
<OBJ><P><INST>< </INST>Discuss the responsibilities of the first police officer who arrives at a crime scene</P></OBJ>
<OBJ><P><INST>< </INST>Explain the steps to be taken to thoroughly record the crime scene</P></OBJ>
<OBJ><P><INST>< </INST>Describe proper procedures for conducting a systematic search of a crime scene for physical evidence</P></OBJ>
<OBJ><P><INST>< </INST>Describe proper techniques for packaging common types of physical evidence</P></OBJ>
<OBJ><P><INST>< </INST>Define and understand the concept of chain of custody</P></OBJ>
<OBJ><P><INST>< </INST>Relate what steps are typically required to maintain appropriate health and safety standards at the crime scene</P></OBJ>
<OBJ><P><INST>< </INST>Understand the implications of the <ITAL>Mincey </ITAL>and <ITAL>Tyler </ITAL>cases</P></OBJ></OBJSET>
<CASE TY="CS"><TTL>JonBenet Ramsey: Who Did It?</TTL>
<P>Patsy Ramsey awoke just after five a.m. on December 26, 1996, and walked downstairs to her kitchen. At the foot of the staircase, she found a two-and-a-half-page note saying that her 6-year-old daughter, JonBenet, had been kidnapped. The note contained a ransom demand of $118,000. Patsy and John Ramsey were in the upper crust of Boulder, Colorado, society. In the span of five short years, John had built his computer company into a billion-dollar corporation. When the police arrived to investigate, it was quite apparent to all that JonBenet was missing. In retrospect, some serious mistakes were made in securing the crime scene—the Ramsey household. Initially, the police conducted a cursory search of the house, but failed to find JonBenet. The house was not sealed off; in fact, four friends along with the Ramsey pastor were let into the home and allowed to move about at will. John was permitted to leave the premises unattended for one and a half hours. One hour after his return, John and two of his friends searched the house again. This time John went down into the basement, where he discovered JonBenet’s body. He removed a white blanket from JonBenet and carried her upstairs, placing the body on the living room floor.</P>
<P>The murder of JonBenet Ramsey remains as baffling a mystery today as it was on its first day. Ample physical evidence exists to support the theory that the crime was committed by an outsider, and also that JonBenet was murdered by someone who resided in the Ramsey household. Perhaps better care at securing and processing the crime scene could have resolved some of the crime’s outstanding questions.</P></CASE></FM>
<BM><H1>Processing the Crime Scene</H1>
<P>As automobiles run on gasoline, crime laboratories “run” on <KT>physical evidence</KT>. Physical evidence encompasses any and all objects that can establish that a crime has been committed or can link a crime and its victim or its perpetrator. But if physical evidence is to be used effectively to aid the investigator, its presence first must be recognized at the crime scene. If all the natural and commercial objects within a reasonable distance of a crime were gathered so that the scientist could uncover significant clues from them, the deluge of material would quickly immobilize the laboratory facility. Physical evidence can achieve its optimum value in criminal investigations only when its collection is performed with a selectivity governed by the collector’s thorough knowledge of the crime laboratory’s techniques, capabilities, and limitations.</P>
<P>Forthcoming chapters will be devoted to discussions of methods and techniques available to forensic scientists for the evaluation of physical evidence. Although current technology has given the crime laboratory capabilities far exceeding those of past decades, these advances are no excuse for complacency on the part of criminal investigators. Crime laboratories do not solve crimes; only a thorough and competent investigation conducted by professional police officers will enhance the chances for a successful criminal investigation. Forensic science is, and will continue to be, an important element of the total investigative process, but it is only one aspect of an endeavor that must be a team effort. The investigator who believes the crime laboratory to be a panacea for laxity or ineptness is in for a rude awakening.</P>
<P>Forensic science begins at the crime scene. If the investigator cannot recognize physical evidence or cannot properly preserve it for laboratory examination, no amount of sophisticated laboratory instrumentation or technical expertise can salvage the situation. The know-how for conducting a proper crime-scene search for physical evidence is not beyond the grasp of any police department, regardless of its size. With proper training, police agencies can ensure competent performance at crime scenes. In many jurisdictions, police agencies have delegated this task to a specialized team of technicians. However, the techniques of crime-scene investigation are not difficult to master and certainly lie within the bounds of comprehension of the average police officer.<SIDEIND NUM="1" ID="MN2.02.001"/></P>
<P>Not all crime scenes require retrieval of physical evidence, and limited resources and personnel have forced many police agencies to restrict their efforts in this area to crimes of a more serious nature. Once the commitment is made to completely process a crime site for physical evidence, however, certain fundamental practices must be followed.</P>
<H2>Secure and Isolate the Crime Scene</H2>
<P>The first officer arriving on the scene of a crime is responsible for preserving and protecting the area as much as possible. Of course, first priority should be given to obtaining medical assistance for individuals in need of it and to arresting the perpetrator. However, as soon as possible, extensive efforts must be made to exclude all unauthorized personnel from the scene. As additional officers arrive, measures are immediately initiated to isolate the area. See <LINK LINKEND="FG.02.001">Figure <FIGIND NUM="1" ID="FG.02.001"/>2–1</LINK>. Ropes or barricades along with strategic positioning of guards will prevent unauthorized access to the area.</P>
<P>Sometimes the exclusion of unauthorized personnel proves more difficult than expected. Violent crimes are especially susceptible to attention from higher-level police officials and members of the press, as well as by emotionally charged neighbors and curiosity seekers. Every individual who enters the scene is a potential destroyer of physical evidence, even if it is by unintentional carelessness. If proper control is to be exercised over the crime scene, the officer charged with the responsibility for protecting it must have the authority to exclude everyone, including fellow police officers not directly involved in processing the site or in conducting the investigation. Seasoned criminal investigators are always prepared to relate horror stories about crime scenes where physical evidence was rendered totally valueless by hordes of people who, for one reason or another, trampled through the site. Securing and isolating the crime scene are critical steps in an investigation, the accomplishment of which is the mark of a trained and professional crime-scene investigative team.</P>
<P>Once the scene has been secured, a lead investigator starts evaluating the area. First, he or she determines the boundaries of the scene, and then establishes the perpetrator’s path of entry and exit. Logic dictates that obvious items of crime-scene evidence will first come to the attention of the crime-scene investigator. These items must be documented and photographed. The investigator then proceeds with an initial walk-through of the scene to gain an overview of the situation and develop a strategy for systematically examining and documenting the entire crime scene.</P>
<H2>Record the Scene</H2>
<P>Investigators have only a limited amount of time to work a crime site in its untouched state. The opportunity to permanently record the scene in its original state must not be lost. Such records not only will prove useful during the subsequent investigation but are also required for presentation at a trial in order to document the condition of the crime site and to delineate the location of physical evidence. Photography, sketches, and notes are the three methods for crime-scene recording (see <LINK LINKEND="FG.02.002">Figure <FIGIND NUM="2" ID="FG.02.002"/>2–2</LINK>). Ideally all three should be employed; however, personnel and monetary limitations often prohibit the use of photography at every crime site. Under these circumstances, departmental guidelines will establish priorities for deploying photographic resources. However, there is no reason not to make sketches and notes at the crime scene.</P>
<H3>Photography.<INST> </INST></H3><P>The most important prerequisite for photographing a crime scene is for it to be unaltered. Unless injured people are involved, objects must not be moved until they have been photographed from all necessary angles. If objects are removed, positions changed, or items added, the photographs may not be admissible as evidence at a trial, and their intended value will be lost. If evidence has been moved or removed prior to photography, the fact should be noted in the report, but the evidence should not be reintroduced into the scene in order to take photographs.</P>
<P>Each crime scene should be photographed as completely as possible. This means that the crime scene should include the area in which the crime actually took place and all adjacent areas where important acts occurred immediately before or after the commission of the crime. Overview photographs of the entire scene and surrounding area, including points of exit and entry, must be taken from various angles. If the crime took place indoors, the entire room should be photographed to show each wall area. Rooms adjacent to the actual crime site must be similarly photographed. If the crime scene includes a body, photographs must be taken to show the body’s position and location relative to the entire scene. Close-up photos depicting injuries and weapons lying near the body are also necessary. After the body is removed from the scene, the surface beneath the body should be photographed.</P>
<P>As items of physical evidence are discovered, they are photographed to show their position and location relative to the entire scene. After these overviews are taken, close-ups should be taken to record the details of the object itself. When the size of an item is of significance, a ruler or other measuring scale may be inserted near the object and included in the photograph as a point of reference. The digital revolution promises to bring enhanced photographic capabilities to the crime scene. For example, individual images of the crime scene captured with a digital camera can be stitched together electronically to reveal a near three-dimensional panoramic view of the crime scene (see <LINK LINKEND="FG.02.003">Figure <FIGIND NUM="3" ID="FG.02.003"/>2–3</LINK>). With the aid of a computer, any area of the scene captured digitally can be enhanced and examined in fine detail.</P>
<P>The use of videotape at crime scenes is becoming increasingly popular because the cost of this equipment is decreasing. The same principles used in crime-scene photographs apply to videotaping. As with conventional photography, videotaping should include the entire scene and the immediate surrounding area. Long shots as well as close-ups should be taken in a slow and systematic manner. Furthermore, it is desirable to have one crime-scene investigator narrate the events and scenes being taped while another does the actual shooting.</P>
<P>While videotaping can capture the sounds and scenes of the crime site with relative ease, the technique cannot at this time be used in place of still photography. The still photograph remains unsurpassed in the definition of detail it provides to the human eye.<SIDEIND NUM="2" ID="MN1.02.002"/></P>
<H3>Sketches.<INST> </INST></H3><P>Once photographs have been taken, the crime-scene investigator sketches the scene. The investigator may have neither the skill nor the time to make a polished sketch of the scene. However, this is not required during the early phase of the investigation. What is necessary is a <KT>rough sketch</KT> containing an accurate depiction of the dimensions of the scene and showing the location of all objects having a bearing on the case.<SIDEIND NUM="3" ID="MN2.02.003"/></P>
<P>A rough sketch is illustrated in <LINK LINKEND="FG.02.004">Figure <FIGIND NUM="4" ID="FG.02.004"/>2–4</LINK>. It shows all recovered items of physical evidence, as well as other important features of the crime scene. Objects are located in the sketch by distance measurements from two fixed points, such as the walls of a room. It is important that distances shown on the sketch be accurate and not the result of a guess or estimate. For this reason, all measurements are made with a tape measure. The simplest way to designate an item in a sketch is to assign it a number or letter. A legend or list placed below the sketch then correlates the letter to the item’s description. The sketch should also show a compass heading designating north.</P><SIDEIND NUM="4" ID="MN2.02.004"/>
<P>Unlike the rough sketch, the <KT>finished sketch</KT> in <LINK LINKEND="FG.02.005">Figure <FIGIND NUM="5" ID="FG.02.005"/>2–5</LINK> is constructed with care and concern for aesthetic appearance. When the finished sketch is completed, it must reflect information contained within the rough sketch in order to be admissible evidence in a courtroom. Computer-aided drafting (CAD) has become the norm to reconstruct crime scenes from rough sketches. The software, ranging from simple, low-cost programs to complex, expensive programs, contains predrawn intersections and roadways or buildings and rooms onto which information can be entered (see <LINK LINKEND="FG.02.006">Figure <FIGIND NUM="6" ID="FG.02.006"/>2–6</LINK>). A generous symbol library provides the operator with a variety of images that can be used to add intricate details such as blood spatters to a crime-scene sketch. Equipped with a zoom function, computerized sketching can focus on a specific area for a more detailed picture. CAD programs allow the operator to select scale size so that the ultimate product can be produced in a size suitable for courtroom presentation.</P>
<H3>Notes.<INST> </INST></H3><P>Note taking must be a constant activity throughout the processing of the crime scene. These notes must include a detailed written description of the scene with the location of items of physical evidence recovered. They must also identify the time an item of physical evidence was discovered, by whom, how and by whom it was packaged and marked, and the disposition of the item after it was collected. The note taker has to keep in mind that this written record may be the only source of information for refreshing one’s memory months, perhaps years, after a crime has been processed. The notes must be sufficiently detailed to anticipate this need.</P>
<P>Tape-recording notes at a scene can be advantageous—detailed notes can be taped much faster than they can be written. Another method of recording notes is to narrate a videotape of the crime scene. This has the advantage of combining note taking with photography. However, at some point the tape must be transcribed into a written document.</P>
<H2>Conduct a Systematic Search for Evidence</H2>
<P>The search for physical evidence at a crime scene must be thorough and systematic. For a factual, unbiased reconstruction of the crime, the investigator, relying on his or her training and experience, must not overlook any pertinent evidence. Even when suspects are immediately seized and the motives and circumstances of the crime are readily apparent, a thorough search for physical evidence must be conducted at once. Failure in this, even though it may seem unnecessary, can lead to accusations of negligence or charges that the investigative agency knowingly “covered up” evidence that would be detrimental to its case.</P>
<P>Assigning those responsible for searching a crime scene is a function of the investigator in charge. Except in major crimes, or when the evidence is very complex, it is usually not necessary to have the assistance of a forensic scientist at the crime scene; his or her role appropriately begins with the submission of evidence to the crime laboratory. As has already been observed, some police agencies have trained field evidence technicians to search for physical evidence at the crime scene. They have the equipment and skill to photograph the scene and examine it for the presence of fingerprints, footprints, tool marks, or any other type of evidence that may be relevant to the crime.</P>
<P>How one conducts a crime-scene search will depend on the locale and size of the area, as well as on the actions of the suspect(s) and victim(s) at the scene. When possible, one person should supervise and coordinate the collection of evidence. Without proper control, the search may be conducted in an atmosphere of confusion with needless duplication of effort. Evidence collectors may subdivide the scene into segments and search each segment individually, or the search may start at some outer point and gradually move toward the center of the scene in a circular fashion (see <LINK LINKEND="FG.02.007">Figure <FIGIND NUM="7" ID="FG.02.007"/>2–7</LINK>). The areas searched must include all probable points of entry and exit used by the criminals.</P>
<P>What to search for will be determined by the particular circumstances of the crime. Obviously, the skill of crime-scene investigators at recognizing evidence and searching relevant locations is paramount to successful processing of the crime scene. While training will impart gener...
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