What is an important consideration when collecting physical evidence from a crime scene?

When collecting physical evidence from a crime scene, preventing biological contamination is crucial. This is important because biological evidence, such as blood, saliva, or other bodily fluids, can yield valuable information that is critical to the investigation. Contamination can compromise the integrity of the evidence, potentially leading to incorrect conclusions or wrongful convictions. Proper handling techniques, such as wearing gloves and using appropriate tools, help preserve the original state of the evidence. Ensuring that evidence is collected and stored in a manner that avoids contamination allows forensic analysts to conduct accurate tests and analyses later on, making it a fundamental principle in crime scene investigation.