Forensic Determination of Time of Death

Purpose: To understand how forensic experts determine the time of death.
Context: Used in crime investigations to provide a timeframe for the death.

Introduction

Forensic experts rely on observable physical changes in the body after death to estimate time of death.

Definition: Paleness of the body post-death due to halted blood circulation.
Timeline: Appears 15-30 minutes after death.
Cause: Lack of blood flow to the skin.

Definition: Cooling of the body to match the external environment temperature.
Process:
- Body temperature drops by 2°C in the first hour, then 1°C per hour.
- Depends on external conditions, like weather and clothing.
Limitations: Not very reliable due to external variable influence.

Definition: Stiffening of muscles post-death.
Timeline:
- Begins 1-2 hours after death with eyelids, fingers, and toes relaxing first.
- Peaks around 12 hours.
- Followed by secondary flaccidity due to muscle degeneration.
Process:
- Caused by calcium release and lack of ATP which prevents muscle relaxation.
- Sequence: Primary flaccidity → Rigor mortis → Secondary flaccidity.
Reliability: More reliable than algor mortis as it is less impacted by external factors.

Definition: Pooling of blood in response to gravity, causing discoloration.
Timeline:
- Starts 15-30 minutes post-mortem, visible by 2 hours.
- Fixes after 6 hours, with purple coloration by 8-12 hours.
Utility: Helps determine body position and time frame of death.
Factors: Lividity patterns convey possible death position and cause.

Estimations: Time of death is presented as a timeframe rather than an exact time due to numerous influencing factors.
Practical Application: Use these signs collectively for a more accurate estimation in crime investigations.

These methods are not infallible due to environmental and situational variations.