洛圣都警察局

Workbook I, CRIME SCENE RECONSTRUCTION, provides the Detective-trainee with all requisite knowledge required to properly reconstruct a crime scene to determine events.


1. 引言

• 犯罪现场重建是通过分析犯罪现场形态、物证的位置与状态，以及对物证的实验室检验，来确定或排除犯罪现场所发生事件与行为的过程。重建不仅涉及科学的现场分析、现场形态证据的解读和物证的实验室检验，还包括对相关信息的系统研究以及合乎逻辑的理论构建。
  
  2. 犯罪现场重建的重要性
  通过厘清导致犯罪现场或所发现物证的各种可能性，来确定犯罪的实际过程通常非常有用。可能需要进行犯罪重建，是维持犯罪现场完整性的一个重要原因。
  需要理解的是，重建不同于重演、再现或犯罪心理画像。重演通常指让受害人、嫌疑人、证人或其他知情人根据其对犯罪的了解，重新演示产生犯罪现场或物证的事件。再现是通过原始现场记录，将必要的物品或动作放回犯罪现场。犯罪心理画像是基于对犯罪现场的心理学和统计分析，用以确定最可能犯罪嫌疑人总体特征的过程。
  这些分析类型各自可能对刑事调查的某些方面有所帮助。然而，它们对于案件的侦破作用有限。重建则基于现场观察能力、检验物证的科学能力以及运用逻辑方法构建理论的能力。
  
  3. 重建的性质
  重建部分基于科学实验，部分基于过往经验。然而，其在法证科学中的步骤和阶段，严格遵循基本的科学原理、理论构建和逻辑方法。它涉及将所有调查信息与物证分析及解读相结合，整合成对犯罪及其相关事件的合理解释。正确的解读、分析以及最终的犯罪现场重建，需要逻辑思维、细致观察以及在犯罪现场调查和物证法证检验方面丰富的经验。
  
  4. 物证与重建的基本原则
  犯罪现场重建的基础，建立在遵循物证法证检验所采用的基本原则之上。洛卡德物质交换原理是所有法证分析的根本基础。尽管缺乏转移痕迹在法证实验室检验中价值有限，但在犯罪现场重建中仍然具有重要意义。
  
  5. 识别
  任何类型的法证分析通常都始于对潜在证据的识别，并将其与无证据价值的物品区分开来。
  一旦发现证据，应尽一切努力并采取一切预防措施来保护、记录和收集该证据。通过实验室分析和物证比对，来鉴别物品、物质和材料，并追溯其来源。
  一旦某物品被鉴别，即可与已知的参考材料或标准品进行比对。根据受检样本与已知样本比对的结果，可以尝试对证据进行个体识别并确定其来源。
  在研究了犯罪现场状况并完成了物证检验之后，才能进行犯罪或案件的重建。
  任何类型的重建通常都始于识别。除非能识别出潜在证据，否则无法进行进一步重建。
  尽管宏观现场和微观现场的检验有所不同，但总体方法保持不变。
  一旦识别出潜在的物证，调查员应始终尽一切可能努力正确记录、收集和保存证据。如有疑问，调查员在对证据进行任何改变之前，应始终咨询该领域的专家。这一点很重要，因为大多数状态证据和形态证据很容易被改变或破坏。必须强调，一旦此类证据被改变，进行重建的能力将受到限制。
  
  6. 鉴定
  鉴定是一个比对过程，利用标准物体或已知物质的种类特征，通过比较物理属性、形态属性、化学属性和生物属性，与从犯罪现场收集的证据物品进行比对。
  即使是对人员的鉴定，也始于同样的逻辑过程，即使用身高、体重、体型、种族、发色和瞳色等属性进行物理类型的鉴定，以纳入或排除某人。然后可以进行更具体的测量来对个人进行个体识别。
  这类物理测量被称为人体测量学，由阿尔方斯·贝蒂荣在20世纪初创立。然而，当人们识别朋友或亲属时，通常结合使用该人的种类特征和特殊特征（个体特征），然后与心中的该人形象进行比较。这种比对过程与鉴别毛发、武器或衣物所使用的过程相同。
  当一件物证被鉴定但无法真正进行个体识别时，它将始终具有相似的种类特征；因此，有时可以就这些特征的相似程度作出陈述。特定证据或特征的相似程度取决于许多因素，从相对容易计算（如血型）到仅限于粗略估计相似性不等。
  
  7. 个体识别
  个体识别是法证科学所独有的；它指的是证明某个特定样本是独一无二的，即使在同种类别的成员中也是如此。它也可以指证明来自犯罪现场的受检证据与一个类似的已知证据样本具有共同来源。
  因此，除了种类特征外，物体和材料还具有可用于区分同种类别成员的个体特征。这些个体特征的性质因证据类型而异，但法证科学家试图利用它们来对物证进行个体识别。
  某些类型的证据可以进行真正的个体识别，但对于其他一些类型，可以接近个体识别的目标。这些类型的个体识别被称为部分个体识别，在某些情况下，它们不过是更精细的鉴定，例如血迹的遗传标记测定、精液证据的DNA分型或油漆碎片的微量元素分析。
  术语“鉴定”有时用来指人身鉴定（对人员的个体识别）。例如，指纹可用于识别个人。这种术语用法不尽理想，因为这实际上是一种个体识别。同样，在尸体无法通过其他方式轻易识别的情况下（例如大规模灾难或火灾和爆炸案件），法证齿科专家可以利用齿科证据和齿科记录进行人身个体识别。
  对物证的鉴定和个体识别分析以及由此得出的结论，是最终重建的重要组成部分。
  
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2. Importance of Crime Scene Reconstruction

• It is often useful to determine the actual course of a crime by limiting the possibilities that resulted in the crime scene or the physical evidence as encountered. The possible need to reconstruct the crime is one major reason for maintaining the integrity of a crime scene.
  It should be understood that reconstruction is different from re-enactment, re-creation, or criminal profiling. Re-enactment in general refers to having the victim, suspect, witness, or other individual re-enact the event that produced the crime scene or the physical evidence based on their knowledge of the crime. Re-creation is to replace the necessary items or actions back at a crime scene through original scene documentation. Criminal profiling is a process based upon the psychological and statistical analysis of the crime scene, which is used to determine the general characteristics of the most likely suspect for the crime.
  Each of these types of analysis may be helpful for certain aspects of a criminal investigation. However, these types of analysis are rarely useful in the solution of a crime. Reconstruction is based on the ability to make observations at the scene, the scientific ability to examine physical evidence, and the use of logical approaches to theory formulations.

3. Nature of reconstruction

• Reconstruction is based partly on scientific experimentation and partly on past experiences. However, its steps and stages, as found in forensic science, closely follow basic scientific principles, theory formation, and logical methodology. It involves consideration and incorporation of all investigative information with physical evidence analysis and interpretation molded into a reasonable explanation of the crime and its related events. Logic, careful observation, and considerable experience, both in crime
  scene investigation and forensic examination of physical evidence, are necessary for proper interpretation, analysis and, ultimately, crime scene reconstruction.

4. Basic principles for physical evidence and reconstruction

• The foundation of crime scene reconstruction is established by following the basic principles used in the forensic examination of physical evidence. The Locard theory of transfer is the fundamental basis of any forensic analysis. Although the lack of transfer has limited value in forensic laboratory examinations, it still has significant importance in crime scene reconstruction.

5. Recognition

• Any type of forensic analysis usually starts from recognition of the potential evidence and separation of this from those items that have no evidential value.
  Once the evidence is located, every effort and precaution should be used to preserve, to document and to collect this evidence. Laboratory analysis and comparisons of physical evidence are used to identify objects, substances, and materials, and to trace its origin.
  Once an item is identified it is then compared with known reference materials or standards. Depending upon the outcome of the comparison between the questioned sample and the known samples, one can then attempt to individualize the evidence and determine its origin.
  Once the crime scene appearance has been studied and the examination of physical evidence carried out, the crime or case can then be reconstructed.
  Any type of reconstruction generally starts from recognition. Unless the potential evidence can be recognized, no further reconstruction can be carried out.
  Although the examination of a macroscopical scene or a microscopical scene is different, however, the general approach remains the same.
  Once potential physical evidence has been recognized the investigator should always make every possible effort to properly document, collect, and preserve the evidence. If a question arises, the investigator should always contact an expert in the field before any alteration of the evidence is done. This is important because most conditional evidence and pattern evidence can be easily altered or destroyed. It is very important to emphasize that once such evidence has been altered, the ability to conduct a reconstruction, will be limited.

6. Identification

• Identification is a comparison process, which utilizes the class characteristics of a standard object or known substance to compare with the evidential item collected from the crime scene by comparing the physical properties, morphological properties, chemical properties, and biological properties.
  Even the identification of persons also starts with the same logical process of physical type of identification that uses properties such as the height, weight, size, race, and hair and eye color, etc. to include or eliminate someone. Then more specific measurements can be carried out to individualize a person.
  The types of physical measurements are referred to as anthropometry, a system developed by Alphonse Bertillon in the early 1900s. However, if one identifies a friend or relative, one generally uses a combination of class characteristics and the special features (individualizing characteristics) of the person and then compares them to a mental picture of the person. This process of comparison is the same process used to identify a hair, weapon, or clothing.
  When an item of physical evidence is identified but cannot be truly individualized, it will always have similar class characteristics; for this reason, statements about how similar these characteristics are can sometimes be made. The degree of similarity of particular evidence or characteristics depends on many factors, and varies from being fairly easily calculated, as in the case of blood groups, to being limited to only broad estimates of similarity.

7. Individualisation

• Individualization is unique to forensic science; it refers to the demonstration that a particular sample is unique, even among members of the same class. It may also refer to the demonstration that a questioned piece of evidence from a crime scene and a similar known sample of evidence have a common origin.
  Thus, in addition to class characteristics, objects and materials possess individual characteristics that can be used to distinguish members of the same class. The nature of these individual characteristics varies from one type of evidence to another, but forensic scientists try to take advantage of them in efforts to individualize a piece of physical evidence.
  Some types of evidence can be truly_individualized, but with some other types an approach to the goal of individualization is possible. These types of individualizations are referred to as partial, and in some cases they are nothing more than refined identifications, such as genetic marker determination from a bloodstain, DNA typing of semen evidence, or trace elemental analysis of paint chips.
  The term identification is sometimes used to mean personal identification (the individualization of persons). Fingerprints, for example, can be used to identify an individual. The terminology is unfortunate, since this is really an individualization. Likewise, dental evidence and dental records may be used by a forensic odontologist in making personal individualizations in situations where dead bodiescannot be readily identified otherwise (such as in mass disaster or in cases of fire and explosions).
  The identification and individualization analyses of physical evidence and the conclusions drawn from them are important ingredients in a final reconstruction.

Workbook I, CRIME SCENE RECONSTRUCTION REPORT WRITING, provides the Detective-trainee with general guidelines.

1. General guidelines for writing an incident report featuring a crime scene reconstruction

• 1. Two examiners should review and sign the report, if practicable and able.
  2. State what materials were reviewed and used as a basis for the report.
  3. Be accurate and in complete agreement with notes taken during the review and reconstruction process.
  4. Use labeled photographs to aid in articulating your observations and comments.
  5. Do not interject or rely on unsubstantiated information.
  6. Clearly state any relevant facts or circumstances not known to you.
  7. If your interpretations are limited due to a lack of data state this.
  8. Do not over-commit or too narrowly limit your opinions and observations:
  (a) - Use words like: consistent with, similar to, most probable, inconsistent with available data or facts, inconclusive, cannot be determined with the available information, etc.
  (b) - Keep an open, objective mind.
  9. Restrict stating opinions until the summary or conclusion; keep facts, observations, and data separate.
  10. Be prepared to objectively evaluate a hypothetical with the stated facts, arriving at a different conclusion or opinion.
  11. Be general; many of the underlying details should be reserved for oral testimony
  (a) - Remember, anything written will be carefully reviewed by other experts.
  12. Stay objective and true to the facts.
  
  Any reconstruction can only be as good as the information provided. Information may come from the crime scene, physical evidence, records, statements, witness accounts, and known data. The process of information gathering and its use in reconstruction show the scientific nature of crime scene reconstruction and will allow for its successful use by investigators.

Workbook I, Part II, CRIME SCENE RECONSTRUCTION FUNDAMENTALS, provides the Detective-trainee with all requisite knowledge required to properly reconstruct a crime scene to determine events at the fundamental level.


1. Reconstruction

• Reconstruction is based on the results of crime scene examination, laboratory analysis, and other independent sources of information to reconstruct case events. Reconstruction often involves the use of inductive and deductive logic, statistical data, information from the crime scene, pattern analysis, and laboratory analysis results on a variety of physical evidence. Reconstruction can be a very complex task, linking many types of physical evidence, stain pattern information, analytical results, investigative information, and other documentary and testimonial evidence into a complete entity. Reconstructions are often desirable in criminal cases in which eyewitness evidence is absent or unreliable. They are important in many other types of cases, too, such as automobile and airplane accidents, fire and arson investigation, and major disasters.

2. Stages in reconstruction

• Reconstruction is considered a scientific fact-gathering process. Reconstruction generally involves a group of actions that will set the stage for crime reconstruction. The following are the five separate stages commonly used in the process
  of reconstruction:
  • 1 -Data collection: all information or documentation information obtained at the crime scene, from the victim, or witnesses. Data including condition of the evidence, obvious patterns and impressions, condition of the victim, etc., are reviewed, organized, and studied.
  • 2 -Conjecture: before any detailed analysis of the evidence is obtained, a possible explanation or conjecture of the events involved in a criminal act may be done, but it must not become the only explanation being considered at this stage. It is only a possibility. There may be several more possible explanations, too.
  • 3 -Hypothesis formulation: further accumulation of data is based on the examination of the physical evidence and the continuing investigation. Scene examination and inspection of the physical evidence must be done. Scene and evidence examination includes interpretation of bloodstain and impression patterns, gunshot patterns, fingerprint evidence, and analysis of trace evidence. This process leads to the formulation of an educated guess as to the probable course of events, a hypothesis.
  • 4 -Testing: once a hypothesis is formulated, further testing must be done to confirm or disprove the overall interpretation or specific aspects of the hypothesis. This stage includes comparisons of samples collected at the scene with known standards and alibi samples, chemical, microscopical and other analyses and testing. Controlled testing or experimentation of possible physical activity must be done to collaborate the reconstruction hypothesis.
  • 5 -Theory formation: additional information may be acquired during the investigation about the condition of the victim or suspect, the activities of the individuals involved, accuracy of witness accounts, and other information about the circumstances surrounding the events. All the verifiable investigative information, physical evidence analysis and interpretation, and experimental results must be considered in testing and attempting to verify the hypothesis. When it has been thoroughly tested and verified by analysis, it can be considered a plausible theory.

3. Pattern analysis in reconstruction

• Pattern evidence is one type of physical evidence encountered at a majority of crime scenes. Often, forensic scientists do not take this type of evidence seriously enough, and think of it as not being very scientific. Pattern evidence at crime scenes is, however, extremely valuable in the reconstruction of crimes and the activity that has taken place at the crime scene. It can be used to prove or disprove a suspect's alibi or a witness's version of what took place at the crime scene, to associate or dissociate the involvement of persons or objects in particular events, or to provide the investigators with new leads or information for further investigation. Pattern evidence is generally created by the contact of two surfaces (persons, vehicles, or objects) that results in the formation of impressions, imprints or markings. These impressions may be from static or stationary contact or dynamic or moving contact and may be two-dimensional or three-dimensional. In some cases, the contact may be a transfer of material from one surface to another resulting in pattern evidence in the form of a stain or deposit. Pattern evidence also results from the fracture, breaking or cutting of an object.
  
  The following is a list of pattern evidence commonly found at different crime
  scenes:
  • 1 Bloodstain patterns
    2 Glass fracture patterns
    3 Fire burn patterns
    4 Furniture position patterns
    5 Track-trail patterns
    6 Tire or skid mark patterns
    7 Clothing article damage or position patterns
    8 Modus operandi and crime scene profile patterns
    9 Projectile trajectory and powder residue patterns
    10 Injury or wound patterns
  
  Pattern evidence found at crime scenes should be carefully documented, processed, enhanced, or collected.
  The techniques used for pattern evidence reconstruction are the same as those examinations of other types of physical evidence: Recognition, Identification, Individualization, Interpretation, and Reconstruction.

4 Bloodstain pattern analysis

• Bloodstain pattern analysis has been defined in several ways. Bloodstain pattern analysis seeks to define the facts surrounding an investigation by the use of the physical nature of bloodstains. It is the evaluation of the static aftermath of bloodshed in an attempt to determine the actions that created the bloodstains found at the crime scene. Oftentimes, the bloodstain patterns provide a window to the past. The totality of these definitions is that the size, shape, and distribution patterns of the bloodstains found at a crime scene where bloodshed has occurred can be used to reconstruct the bloodshed event(s). The bloodstain pattern analysis is in some cases more useful and significant than the serological or DNA information obtained from the blood.
  The bloodstain patterns reveal not who but what with regard to the circumstances of bloodshed. The what of bloodshed is the result of careful examination and study of the bloodstains appearance at the crime scene.
  
  The following are some examples of how reconstruction can be made by the study of the bloodstain evidence:
  • Direction of travel of the blood droplets.
    Distance of blood source to target surface.
    Angle of impact of blood droplet.
    Type of blood droplets.
    Determination of blood trails, their direction, and the relative speed of motion.
    Nature of the force used to create the bloodshed.
    -Nature of the object used to cause bloodshed, the number of blows involved, and
    relative location of persons/objects near bloodshed.
    Sequencing of multiple events associated with the bloodshed.
    Interpretation of contact or transfer patterns.
    Estimation of elapsed time and volume of bloodshed

5. Glass fracture patterns

• Broken glass at crime scenes can sometimes aid in reconstruction, providing information about the events which took place, and assisting in proving or disproving an alibi or witness's story. Glass fracture patterns are most often associated with burglary, criminal mischief, shooting incidents, and fire scenes.
  The most common types of information that can be obtained by studying glass fracture patterns are:
  • Direction of impact force applied (from inside out or outside in).
    Approximate force of impact.
    Approximate angle of impact of force.
    Determination of the type of glass fracture.
    Determination of the sequence of firing, direction of firing, and the type of firearm for the projectile holes present.
    Estimation of the fire temperatures, direction of fire travel, and the intensity of heat from the melted glass.
  The use of glass fracture patterns in crime scene reconstruction relies on careful recognition, documentation, and study of radial and concentric glass fracture markings. Other information for reconstruction is obtained by analysis of rib marks, spatial relationships, crack marks, and the condition of any melted glass. To conduct even a basic reconstruction based on glass fracture evidence, investigators should be familiar with the different categories of glass and generally how each type of glass fractures. Glass is an amorphous, super-cooled liquid, composed primarily of silicon dioxide (sand). There are three general classes of glass: plate, tempered, and safety.
  Each type of class has certain characteristics, and will fracture differently.
  
  Plate glass is a common variety of glass used to make windows and mirrors. When plate glass is exposed to a force significant enough to rupture the surface tension and break the glass, characteristic pie-shaped glass shards are formed. If broken glass remains in the frame the observed fracture pattern will consist of a center point, where the force contacted the windowpane, with radiating (radial) fracture lines going out from the center point. In addition, there will be fracture lines running perpendicular to the radial lines, concentric fracture lines. By carefully examining a broken edge of a piece of glass along a radial line, you can determine the direction of force. This analysis is helpful in determining from which side of the glass the window was broken. Investigators can use this information to confirm a false burglary report by showing that the window was broken from the inside out rather than outside in as reported by the homeowner.
  
  Safety glass is found in automobile windshields. Basically, safety glass is two separate panes of plate glass adhered together with a clear laminated layer. While this glass fractures in a similar way to plate glass it remains intact after breaking due to the laminate layer. Safety glass was designed to reduce injuries to passengers should they be propelled into the windshield as the result of a traffic accident. Caution must be exercised when interpreting safety glass fracture patterns in that there are two separate panes of glass, which will have independent radial and concentric fractures. Since safety glass remains intact it can provide valuable information in shooting incidents. The direction of each gunshot can be determined by locating the crater, which
  is located on the side of glass facing the impacting force. Also, if more than one bullet penetrates the windshield it is possible to sequence the shots if the bullet holes are close enough together that their separate radial fracture lines converge. The subsequent bullet hole can be determined because radial lines from that bullet hole terminate where they meet the existing radial line from the prior fracture.
  
  Tempered glass is a single pane glass that is durable and difficult to fracture due to its significant surface tension. When enough force is applied to break this surface tension the entire pane of glass fractures into thousands of small pieces, commonly referred to as dicing. Tempered glass is used in side windows of automobiles. In most cases a vast majority of the diced glass falls from
  the window frame, into the car and on the ground.

6. Fire burn patterns

• Fire burn patterns often provide information on the various factors which led to or caused a fire. Detailed study of the burn patterns generally helps in determining the point of fire origin, the direction of fire travel, and the degree of damage of a fire, which may contain clues for arson investigations.
  The following is a partial list of common patterns found at fire scenes:
  • Inverted cone or V pattern
    Multiple points of origin burn patterns
    Low burn pattern configurations
    Depth of charring patterns or alligator patterns
    Trailer patterns
    Smoke stain pattern, Melted material patterns
    Concrete spalling patterns
  
  Every fire forms a pattern that is determined chiefly by the configuration of the environment, the availability of combustible material, and the type and intensity of the fire. From a study of the fire patterns and a determination of any deviations from normal or expected patterns, an experienced fire investigator can reconstruct a fire scene.

7. Furniture position patterns

• At an indoor crime scene, the position and condition of furniture often yields information about the events that caused the pattern, their sequence, and possible actions of perpetrators and victims. Displaced or broken furniture can indicate that a struggle took place. Patterns of disarray in ordinary or expected furniture placement or condition may further reveal actions taken by suspects or witnesses.

8. Track-trail patterns

• Occasionally, track-trail patterns are encountered at crime scenes. Proper interpretation of them can yield information about how many persons were present at a scene, whether they were moving about, the nature of the movement (walking, running) and the direction of travel, and whether heavy objects were being carried or dragged. Some of these types of patterns can give class characteristic information or data about the individual responsible for producing the patterns, such as shoe size, stride length, sex, weight, or any abnormalities in movement or gait.

9. Tire and skid mark patterns

• Tire or skid mark patterns are often seen at outdoor crime scenes, and can provide important reconstruction information for the crime scene investigator. The value of skid mark patterns in traffic accident reconstructions is well known and documented. However, the use of these patterns in crime scene investigation and reconstruction is often neglected. These markings can yield information about the number and types of vehicles involved, the possible speed of travel, direction of travel, whether or not brakes were applied, and whether turns were made.

10. Clothing or article patterns

• This type of pattern evidence can be subtle or, at times, very obvious! Detailed observation, measurement, documentation, and correct interpretation of these patterns can be valuable and essential in crime scene reconstruction. Some examples of the types of information that can be obtained from these patterns are whether a suspect ransacked a scene, proof or disproof of an alibi, direction and route taken by a suspect, physical contact between persons, persons and vehicles, or between vehicles, disturbances of expected patterns at the crime scene, and possible information about the sequence of events.

11. Modus Operandi and scene profile patterns.

• These patterns are more subtle, and require careful observation, as well as extensive knowledge of criminals and details of their previous crimes. Modus operandi (MO) patterns can link apparently unrelated crimes together at the investigative stage. These patterns include information such as methods used to gain entry to a premises, types of weapons preferred, types of force used, types of language used, the sequence of actions followed by the suspect, types of property taken, and the types of any materials left behind at the scene. Scene profiles often reveal information with regards to identification of primary v. secondary scenes; active scenes v. passive scenes; organized scenes v. disorganized scenes.