Editors

AnttiSajantila

Estimating the Time of Death

Determining the time of death may be important for
- medicolegal criminal cases
- insurance, compensation, and pension
- the assessment of reliability of the stated cause of death.
All procedures and observations should be recorded systematically. Conclusions can be drawn later on.
Always consult with a medical examiner in your county when
- the determination of the time of death is particularly important (as in homicide), in which case several methods should be used together
- you feel insecure about applying the methods
- you draw conclusions based on measurements of temperature or on laboratory investigations.
Actions and observations when estimating the time of death: see table T1
Development of post-mortem changes: see picture F1

Actions and observations	Note / record
Undress the deceased	Take off all clothes; record the type of clothing and the number of cloth layers
Time by the clock	Time at the start and end of the investigation
Post-mortem livores	Location and disappearance on pressure
Rigor mortis	One joint at a time starting at the jaw and ending at toes
Temperature measurement	Rectal temperature measurement, 10 cm deep, lasting for 10 min; in case of homicide, several measurements at 30 min intervals Register the exact time of the temperature measurement(s) Register the air temperature and the clothing, weight and build of the deceased
Decomposition changes	Start at the abdominal wall Venous pattern becomes visible The skin is detached Maggots / flies
Other observations	Dates of arrived mail, receipts, dates of perishable foods, times of telephone calls, etc. Leaves/snow under the head of the deceased

The temperature is measured without moving the body or changing the clothing, see table T1.
Environmental temperature is measured close to the place where the rectal temperature is measured.
The estimated time should be adjusted on the basis of body build, clothing, and the thermal conduction of the surface on which the body lies. The margin of error is ± 2 hours during the first 10 hours after death, and thereafter ± 3-4 hours.
Depending on the case, it may be necessary to perform several temperature measurements e.g. at 1- and 2-hour intervals.

All joints should be examined systematically. At room temperature
- the jaw and neck become stiff in 2-4 hours
- the fingers and toes become stiff next
- the large joints (elbow, knee and hip joints) are the last to become stiff.
Rigor mortis is fully developed in 6-8 hours. It disappears in the opposite order as it was developed when putrefaction starts, after about 2 days at room temperature.
The time of these changes to occur is variable. E.g. fever, hot weather and exercise before death accelerate the process, and cold weather and a well-developed musculature delay the process.

Blood discolours the lower body parts, with the exception of the parts pressed against the ground. In a supine position the livores appear in the following order:
- the sides of the thorax
- the neck and ears
- united
- fully developed 10-12 hours after death.
The livores disappear on pressure or move when the position of the body is changed if no more than 4-6 hours have elapsed since death.
Patients who have died of blood loss do not usually have livores.
Putrefaction destroys the livores.

Attention should be paid to
- drying (eyes, fingers, lips)
- putrefaction (the first sign is the green colour of the stomach skin)
- eggs or larvae of insects.