Forensic Evidence Management

From the Crime Scene to the Courtroom

Ashraf Mozayani, Casie Parish-Fisher, Ashraf Mozayani, Casie Parish-Fisher

• Publisher: CRC Press
• Year: 2017
• eBook ISBN: 9781351650946
• Edition: 1
• Topic: Jura
• Subtopic: Strafrecht

"Evidence management has become a crucial component for the law enforcement community. I truly believe this book is essential in assisting criminal investigators and a valuable resource for managing evidence."—Jeremiah Sullivan, Chairman, Board of Directors, Texas Division of the International Association for Identification; Senior Crime Scene Specialist (Retired). Austin Police Department

As technology and technical applications continue to advance in the forensic sciences, the undertakings at crime scenes have become even more critical. Crime scene investigators must ensure that evidence is properly collected, document, packaged, and stored in a manner that maximizes the ability of laboratories to derive meaning and results from the evidence provided them.

Forensic Evidence Management: From the Crime Scene to the Courtroom provides best practices policies for forensic science entities and their employees to maintain chain of custody and evidence integrity throughout the course of evidence collection, storage, preservation, and processing.

The focus of the book will be to address the issues related with evidence handling and analysis inside the forensic laboratory, in particular, and to offer best practices and guidelines from leading forensic experts in the field. Forms of evidence covered include biological, chemical, trace, firearm, toolmark, fingerprint, and a host of others types recovered at crime scenes. The book concludes with a chapter on ethics, bias, and ethical practices in evidence handling in the field and laboratory analysis.

Test Bank and PowerPointTM slides are available for download from the Taylor & Francis ancillary Web site for qualifying course adopters.

Crime Scene Dynamics	1
MICHAEL KESSLER AND CASIE PARISH FISHER

Contents

Overview

Scene Security

Scene Integrity

Scene Walk-Through and Initial Documentation

Evidence Recognition and Observation

Scene Documentation

Notes

Diagrams/Sketches/3D Scanning

Photography

Videography

Collection

Bibliography

Overview

Crime scene investigation is the first step of the forensic investigation process and the handling of a crime scene establishes the quality and quantity of information available for the investigation and ultimately the information available as evidence in court. The proper identification, documentation, collection and preservation of physical evidence at a crime scene are the critical first steps in ensuring the integrity and admissibility of the physical evidence. No other stage in the investigative process has such potential to impact every other stage. Any failures during this vital stage in the forensic investigative process can taint the evidence and render any further forensic analysis inadmissible.

The integrity and chain of custody of each item of evidence are initially established at its point of collection from a location associated with a crime. A crime scene may be the location where the primary offense occurred or a secondary location such as a vehicle, residence or any other object that may produce physical evidence of value to the investigation. Therefore, the responsibility of ensuring the integrity and admissibility of physical evidence is not incumbent upon only law enforcement personnel specifically tasked with crime scene investigation duties, but all personnel who may come into contact with, handle or collect physical evidence.

Additionally, all items of physical evidence related to a crime may not be initially identifiable as such. Abandoned or found property may materialize into evidence critical to an investigation and should be documented, collected, packaged and stored in a manner that maintains the integrity and chain of custody of the item. While the resources and time applied to the abandoned or found property scenes will undoubtedly differ from those applied to a recognized crime scene, the general principles of sound evidence management will not change. This universal application of property and evidence collection standards to a greater or lesser extent at all scenes provides a solid foundation for further forensic analysis and judicial proceedings.

Scene Security

Principal to the successful management of evidence at the crime scene is scene security. Responding law enforcement officers – after ensuring no immediate threats remain and rendering emergency care – must secure persons on the scene and the scene itself. After an initial assessment of the scene, establishing a scene perimeter and controlling access to the scene are necessary to the safeguarding of scene integrity, preservation of evidence and minimizing contamination. Once boundaries have been established and the scene is clear of unauthorized persons, the entry and exit of all persons must be controlled and documented to maintain the integrity of the scene. This entry/exit log documentation should include approximate arrival time for all first responders and any other personnel who arrived prior to the establishment of a log. Dispatch logs may be used to supplement arrival times for first responders. The entry/exit log should be maintained until the release of the scene.

Scene Integrity

The condition of the scene as found by the first responding officers should be maintained and documented. Excepting disruptions caused by the rendering of medical care or safety concerns, neither the scene nor the involved parties (suspect, victim) should be altered. As far as possible, physical evidence should be preserved in the original state in which it was found. Once a scene has been fully secured, all items inside the scene should also be considered secured. Any items or weapons within the scene, including firearms, should not be moved unless necessary for the safety and well-being of persons on scene. Any disruptions to the scene (or any items within it) from the condition found by initial responding officers must be documented in their report. Any manipulation of the scene including for medical or safety reasons must be documented. Undocumented changes to the scene and items within it degrade the evidence, bring the investigating agency’s credibility into question and are likely to negatively affect forensic analysis and lead to the inadmissibility of the physical evidence.

For example, should the first officer to arrive on scene to a suicide disturb the scene (whether out of curiosity, negligence or for safety reasons) by moving a revolver located adjacent to the decedent’s hand by picking up the firearm; opening, inadvertently rotating and then closing the cylinder; and then placing the revolver several feet away from the decedent – all without documenting those actions – would undoubtedly cause errors in further scene and forensic analysis. Moving the revolver and altering the cylinder position would alter the scene and the evidence causing investigators to pursue the investigation as a homicide as the altered scene and evidence point in that direction. By documenting his actions and reasoning, the responding officer can easily account for the scene and physical evidence being found by forensic investigators in a condition that supports a homicide hypothesis despite the incident being a suicide.

To ensure the safety of personnel and the integrity of the scene, access should be limited to personnel directly involved with processing of the scene. Contamination control can be exercised through the utilization of established entry and exit routes; collection of elimination samples from responders and investigators; use of personal protective equipment (PPE); cleaning and sanitizing tools, equipment and PPE between contact with samples and between scenes; and utilizing single-use or disposable equipment when collecting samples.

Scene Walk-Through and Initial Documentation

After assessing the scene to determine the type and level of investigation to be conducted and developing a plan for the coordinated identification, documentation and collection of physical evidence; the preliminary documentation should be prepared. Preliminary documentation includes notes and rough scene sketches of the location as they were found by investigators during an initial walk-through. This initial documentation may include the investigator’s own relevant observations of the condition of the crime scene and items within it as well as information from first responders that relates to changes made to the crime scene due to medical intervention or for safety reasons during the time period between the initial response and the arrival of the investigator. While the first responders may relay such information to investigators, the investigators should request that the first responders include the information in their own reports.

The initial walk-through also serves as the first opportunity for investigators to identify valuable and fragile physical evidence. At this point, consideration should be given to whether additional resources are needed to fully process the scene, the order in which evidentiary items are collected and the order of scene processing.

Evidence Recognition and Observation

Forensic investigation depends on forensic and investigative professionals’ ability to recognize physical evidence at a scene as having potential investigative or evidentiary value. This consequently relies on the training and experience of the personnel involved. While the formation of alternate hypotheses should not be constrained, information from first responders, victims and witnesses may be used to form an initial hypothesis as to what physical evidence may be relevant. The investigator should look for anything that may be out of place, as well as focusing on items that are dictated by the initial hypothesis. The recognition, documentation, collection and preservation of suitable and sufficient physical evidence play a vital role in subsequent analytical and judicial processes.

Once physical evidence is determined to be of potential evidentiary value, the preservation of that evidence becomes of paramount importance. Generally, the collection of items of evidentiary value follows thorough documentation of the scene and the items in situ; however, the presence of certain transient types of evidence, exigent environmental conditions or certain scene considerations may require collection of the items or samples before complete documentation occurs. Such transient sample types include trace evidence (hairs/fibres) in outdoor or unenclosed scenes. Environmental conditions such as rain or snow pose a substantial threat to exposed biological samples while winds can threaten numerous types of evidence in outdoor scenes. Scene considerations such as civil unrest, proximity to waterways or storm sewers may threaten the loss or destruction of physical evidence. In any circumstance, the necessity to exigently collect evidentiary items – along with any damage done to the item prior to collection – should be thoroughly documented in the investigator’s report.

Scene Documentation

Recording the condition, position and location of physical evidence prior to collection provides critical information and context to the investigation. A well-documented scene ensures the integrity of the investigation and provides a permanent record for later evaluation. Failure to accurately and completely document the crime scene may negatively impact follow-on forensic analysis including crime scene reconstruction and judicial proceedings. In general, the position of bodies and of significant forensic material should be recorded prior to removal, collection or alteration.

Documentation includes notes, diagrams/sketches/3D scanning/metrology, photography, videography, etc. The initial assessment of the scene will determine the type(s) of documentation necessary for the scene investigation.

Notes

Notes should be taken continuously throughout the scene investigation. Included in the documentation should be observations of the scene as it appears and items deemed to be of potential evidentiary value. In addition to contextual data about the scene (date, location, time) transient evidence (odours, sounds) and conditions (weather, temperature) should also be noted. Just as any processing done on scene should be documented, so should any situations which require deviation from standard procedures. Audio recording may also be used to record observations and actions at a scene. The recording should include...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Foreword
• Acknowledgements
• Contributors
• 1 Crime Scene Dynamics
• 2 Evidence Tracking and Secure Storage
• 3 Evidence Management of Fingerprints
• 4 Biological Evidence: Collection, Transportation and Preservation
• 5 Sexual Assault Evidence: Collection Techniques
• 6 Evidence Management Best Practices in Medicolegal Death Investigation
• 7 General Principles and Techniques of Trace Evidence Collection
• 8 Firearms Evidence: Documentation, Collection and Preservation
• 9 Introduction to Drug Evidence Handling Procedures
• 10 Evidence Collection and Management for Forensic Toxicology Analysis
• 11 Questioned Documents
• 12 Forensic Digital Evidence
• 13 Evidence Collection for Arson Cases
• 14 Forensic Art and Imaging: Best Practices for Evidence Handling
• 15 Ethical Issues, Bias and Other Challenges to Forensic Evidence Management
• Index