Section 1.5: Crime Scene Procedures

If you ask any experienced detective or crime scene technician to identify the top five most serious and common problems they find at crime scenes, you will inevitably hear the same response within those five: Curious officers, supervisors, and detectives contaminate crime scenes with disturbing regularity.

Tackling Contamination at Crime Scenes

Contamination at crime scenes is a pervasive issue, with even seasoned law enforcement personnel sometimes contributing to the problem. The challenge lies in managing who accesses the scene to preserve the integrity of vital evidence. Implementing strict, well-understood departmental policies, coupled with comprehensive training for all law enforcement and support staff, is essential to mitigate this risk.

Broadening the Scope of Training

Effective contamination prevention hinges on educating the entire police department, not just specialists like crime scene technicians or detectives. Since first responders are often the earliest at the scene, their understanding of contamination risks and proper crime scene protocols is crucial. This training must detail the critical importance of limiting scene access to those directly involved in the investigation.

Dispelling Hollywood Myths

Popular media often misrepresents crime scene investigations, showing crowded scenes managed by multiple officers and detectives without concern for evidence integrity. In reality, crime scene management is methodical and disciplined, focusing on preserving evidence and minimizing access to only those essential for the investigation.

The Consequences of Overcrowding

Unrestricted access to crime scenes can severely compromise evidence, especially with sensitive materials like DNA, blood spatter, or trace evidence. For instance, the collection of hair samples or the analysis of footwear and tire track impressions can become significantly challenging or even impossible if the scene is contaminated by excessive foot traffic. Each unnecessary presence not only risks the direct contamination of evidence but also dilutes the scene’s overall integrity, potentially rendering critical information unusable.

🔍 Reflect

Why is comprehensive training across all levels of law enforcement crucial in preventing crime scene contamination, and how does media portrayal of crime scene investigations contrast with real-world practices?

Supervision in Maintaining Crime Scene Integrity

In safeguarding the integrity of a crime scene, the leadership and example set by supervisory personnel are invaluable. Their actions and adherence to policy not only guide the behavior of line officers but also ensure the preservation of forensic and legal evidence integrity, crucial for its admissibility in court.

Setting Standards Through Leadership

Supervisory figures, including detectives who oversee investigations, hold the key responsibility of restricting access to crime scenes. This limitation is not about exerting authority but about protecting the evidence’s scientific and legal validity. Their approach to managing the scene—demonstrating restraint and respect for protocols—serves as a powerful model for other officers.

Enforcing Best Practices

The behavior of leaders within a crime scene has a significant impact on the department’s culture and the professionalism of its staff. Supervisors are expected to lead by example, adhering to departmental policies that reflect best practices in crime scene management. This includes maintaining meticulous entry and exit logs, ensuring that anyone entering the scene has a clear investigative purpose, and avoiding unnecessary disturbance of the scene.

Practices such as casual inspection of areas not relevant to the investigation (e.g., opening cabinets or drawers without cause) not only risk contaminating evidence but also undermine the professionalism and discipline critical to effective law enforcement.

Upholding Professional Standards

For supervisory personnel, the challenge and duty lie in being paragons of the protocols they expect others to follow. Their commitment to rigorously following guidelines and setting a positive example is crucial in teaching officers the importance of preserving crime scene integrity. It’s this level of discipline and adherence to best practices that elevates the entire department’s professionalism and effectiveness in conducting investigations.

🔍 Reflect

How do the conduct and discipline of supervisory personnel at a crime scene influence the behavior of line officers and the overall quality of the investigation?

Implementing Effective Written Policies

The creation and enforcement of comprehensive written policies are fundamental responsibilities of departmental leadership in ensuring the protection and preservation of crime scenes. These policies are pivotal not only in guiding officers in the field but also in safeguarding the integrity of evidence crucial for successful prosecutions.

Establishing Clear and Enforceable Policies

For these policies to be effective, they must be taken as seriously as any other directive within the department. It’s essential that supervisory personnel enforce these guidelines stringently, ensuring that all officers, regardless of their rank, understand the critical nature of crime scene integrity. Recognizing the role of patrol officers as often the first on the scene, the policy must underscore the importance of their actions in securing and preserving the scene from the outset.

Collaboration in Policy Formulation

In developing these policies, input from district attorneys and crime laboratory staff can be invaluable. Their experiences, especially in cases where evidence contamination has led to judicial setbacks, can provide practical insights into crafting policies that address real-world challenges.

Key Components of Crime Scene Policies

A well-structured crime scene policy should aim to:

• Limit Scene Access: Implement uniform procedures to restrict unnecessary entry into crime scenes, emphasizing that curiosity does not qualify as a valid reason for scene access.
• Control Entry and Exit: Designate a single entry point for the crime scene, with a dedicated officer logging each individual’s entry and exit, reasons for their presence, and their rank or role.
• Mandate Documentation: Require all personnel entering the scene to submit a standardized report of their activities and interactions within the scene to trace their impact on the investigation.
• Require Elimination Samples: Ensure anyone who enters the scene is prepared to provide elimination samples, such as hairs or fingerprints, to distinguish between evidence and contaminants.
• Accountability for Senior Officers: Address “tourism” by holding the highest-ranking officer on the scene accountable for all present, discouraging unnecessary visits by those wishing to “have a look around.”

Supporting Officers in Enforcing Policies

Given the potential difficulty for patrol officers in enforcing these rules, especially with higher-ranking officials, the clarity and authority of written policies are crucial. These policies must be practical and enforceable, empowering officers to uphold crime scene integrity without hesitation.

Training and Implementation

The effectiveness of any policy is contingent upon its implementation. Regular training, starting from the academy and reinforced through continuous education, ensures that all department members understand the significance of these policies. Highlighting the consequences of contamination emphasizes the collective responsibility in crime scene management.

In essence, the development of clear, actionable policies for crime scene management, backed by comprehensive training and strict enforcement, is essential in maintaining the integrity of investigations and ensuring the admissibility of evidence in court.

🔍 Reflect

How do detailed and enforceable written policies contribute to the integrity of crime scene investigations and the prevention of evidence contamination?

References and Further Reading

• Technical Working Group on Crime Scene Investigation. (2000).  Crime Scene Investigation: A Guide for Law Enforcement.  Available:  https://www.ncjrs.gov/pdffiles1/nij/178280.pdf

 

Modification History

File Created:  05/02/2019

Last Modified:  04/03/2024

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