In criminal investigations, preserving the integrity of physical evidence is crucial. Whether it’s a trace of blood, a shell casing, or a handwritten note, how the evidence is stored can determine its admissibility in court. One of the most essential tools in crime scene investigation is the crime scene evidence bag. Designed specifically to protect, preserve, and secure physical evidence, these bags have several key features that make them indispensable for law enforcement and forensic professionals.
To understand the importance of properly storing and handling evidence, it’s helpful to learn about the chain of custody—a fundamental legal principle in forensic science.
1. Tamper-Evident Seals
One of the most critical features of a crime scene evidence bag is its tamper-evident seal. These seals ensure that once the bag is closed, any attempt to open or alter it will be immediately visible. This not only prevents unauthorized access but also protects the credibility of the evidence if it’s used in a legal proceeding. A compromised seal could call the entire chain of custody into question, leading to potentially devastating consequences in court.
2. Durable, Tear-Resistant Material
Evidence bags must be made of strong materials that resist tearing, punctures, and degradation. Depending on the type of evidence, bags can be made from heavy-duty plastic or breathable paper. Plastic bags are typically used for non-biological items like weapons, drugs, or personal belongings. Paper bags, on the other hand, are ideal for biological evidence such as clothing with blood or bodily fluids, as they prevent moisture buildup and mold growth.
3. Writable Surface or Pre-Printed Label
Proper labeling is essential for identifying and tracking evidence. Most evidence bags include a writable surface or a pre-printed label with designated fields for information such as case number, date and time of collection, name of the collector, and description of the item. This helps establish a clear, unbroken chain of custody from the crime scene to the courtroom.
4. Multiple Size Options
Evidence collected at a crime scene can vary greatly in size—from small bullet casings to large items like clothing or tools. That’s why crime scene evidence bags come in multiple sizes. Having the right-sized bag ensures that the evidence fits securely without being damaged or bent, which is especially important when handling delicate materials like documents, electronics, or hair samples.
5. Sequential Barcodes or Serial Numbers
Many modern evidence bags feature unique serial numbers or barcodes, allowing for easy tracking and identification throughout the investigation. These identifiers are especially useful for large-scale investigations involving multiple items of evidence, helping ensure that nothing is lost, mixed up, or mishandled.
Final Thoughts
Crime scene evidence bags may seem like a small detail, but they play a critical role in preserving justice. From tamper-evident seals to clear labeling and durability, their features are designed to protect the truth—one sealed bag at a time.
