Describe the proper methods for collecting and documenting firearm evidence at a crime scene, ensuring safety and preservation of ballistic markings.

Collecting firearm evidence requires strict adherence to safety protocols and careful documentation to preserve its evidentiary value, particularly ballistic markings which are unique to a specific firearm. Before handling any firearm, it must be treated as loaded until proven otherwise. Safety is the paramount concern. Prior to collection, the firearm's condition (e.g., cocked, safety on/off, magazine inserted) should be documented in detail, including photographs and notes. To render the firearm safe, the magazine should be carefully removed (if applicable) and the chamber should be cleared of any live rounds. These rounds should be collected as separate pieces of evidence. The firearm should then be secured using zip ties or evidence tags to prevent accidental discharge during handling and transport. When handling the firearm, it should be gripped on areas that are least likely to contain fingerpr....