Which of the following is an example of very short-lived evidence?

• A. Blood
• B. Witnesses
• C. BAC
• D. Fluids

Answer: (C)

Very short-lived evidence is evidence that can change or disappear quickly, so it must be collected promptly. BAC fits this because the amount of alcohol in the blood changes rapidly as the body metabolizes and eliminates it. The reading can drop to near zero within hours, so delaying collection or testing can make the evidence disappear or become unreliable. In contrast, blood samples can be preserved for later analysis, fluids aren’t necessarily changing as quickly in the same measurable way, and witness statements, while they can fade with time, are not a chemical measurement that vanishes as quickly. So BAC is the best example of evidence that is most time-sensitive.