Practice, Practice, Practice: Taking Special Care to Manage Crime Scene with Radioactive Material and Contaminated Evidence
Radioactive material can end up on crime scenes as a result of intentional malicious acts such as theft or trafficking of material. It can also be the result of criminals causing unintentional damage to machinery that contains radioactive sources. Regardless of the cause, a crime scene at which radioactive material may be present, requires special care. In cooperation with the Armenian Nuclear Regulatory Authority, the IAEA created a mock crime scene with radioactive material and contaminated evidence to simulate investigation and evidence collection in a safe and secure manner.
During an investigation into criminal activities, law enforcement officers identify a facility where it appears that criminals have been planning an attack involving radioactive material.
First responders work with a radiological crime scene manager and radiation specialist to assess initial information and common hazards that may be present on the scene. Based on the initial assessment, they sketch the crime scene, identify approach routes, determine the safety perimeter, develop emergency procedures, and outline the search procedures for when they arrive on the scene.
Evidence labels are essential for establishing chain of custody. Evidence labels include description of the item, when, where and how it was obtained, name and signature of the person obtaining the evidence, and an identifier associated with the particular crime scene. Proper labelling helps maintain integrity of the evidence for further analysis and potential legal processes.
Members of the evidence recovery team, with the assistance of a radiation specialist, put on personal protective equipment (PPE) to prevent contamination of their own persons and of environment and property beyond the identified crime scene perimeter upon their exit.
On crossing of the crime scene perimeter, the entry of the evidence recovery team is logged and timed. This log is used to maintain access control to the crime scene and ensure that law enforcement officers’ exposure to potential radiation on the scene is within the nationally determined limits.
Officers place the equipment for evidence recovery and contamination monitoring close to, but outside of the crime scene. The equipment includes a contamination meter, evidence packaging, extenders for collecting evidence at a safe distance, and cotton swabs for checking contamination of the evidence packaging.
The initial survey provides a record of the radiation levels on the scene and is conducted at the direction of the radiological assessor. Based on the record, the radiological assessor determines the safe working processes. The evidence recovery team also starts to identity items of evidential interest and reports back to the crime scene manager to update the initial investigative and evidence collection plan, as needed.
Detailed assessement, following the updated evidence collection plan, provides the initial identification of the radiological isotope. Depending on the radiological isotope present, the radiological assessor determines protective measures that must be adopted by the evidence collecting team, including distance from which the isotope or contaminated evidence may be safely captured.
The IAEA provides radiation detection equipment and training for use to governments, upon request, to help national authorities’ build capacity in responding to nuclear security events.
Prior to the collection of any evidence, the entire scene is photographed to ensure an accurate reconstruction of the crime scene. Such reconstruction is most likely needed as part of the investigation and further legal proceedings.
Evidence is collected according to the evidence collection plan. Priority is given to the evidence which may identify perpetrators, further possible targets, or other crime scenes.
The evidence recovery team collects evidence using extenders to maintain a safe distance from the radiological hazard. A colleague holds open an evidence bag in way that ensures that the outside of the evidence bag is not contaminated during the depositing process.
The evidence recovery team checks the outside of the bag for contamination.
Outside of the safety perimeter of the crime scene, the collected evidence is handed over to the evidence custodian. The evidence custodian makes the first entry into a chain of custody log for the particular item of evidence. Chain of custody is essential for ensuring admissibility of evidence during potential legal prosecution of the perpetrators.
Repeated practice maintains the readiness of the responders to investigate a radiological crime scene and recover evidence for nuclear forensics analyses and potential legal proceedings. The radiological crime scene management process, as practiced by the participants, is outlined in the IAEA publication Radiological Crime Scene Management (Nuclear Security Series No.22-G) and is based on the international good practices collected by the IAEA.
