Not necessarily.
There are methods to calculate the time of death when some unknown to examiner time passed between the time when the person died and the body was discovered.
In
forensic science, the time of death is one of the most crucial pieces of information that can be obtained at the crime scene and in the dissecting-room.
One of methods is based on the level of food consumed prior to death.
As M. and K. purchased some food and is known that they purchased pasta, they most likely ate that pasta carbonara some time between 1:45 (time when they purchased pasta recorded via live sream from food truck) and 2:52 am when they both switched their phones and presumambly fell asleep at that time.
If the stomach, at autopsy, is found to be filled with food, and digestion of the contents not extensive, it is reasonable to assume that death followed shortly after the meal, which i think is what ME recorded in this case: time of death within circa 1 hr of eating pasta.
If the stomach is entirely empty, death probably took place at least 4 to 6 hours after the last meal.
There are other ways to calculate time of death accurarelly.
- Calculating time of death using rigor mortis (change in the rigidity of the body); and
- Calculating time of death using algor mortis (change in the temperature of the body).
If the body feels warm and no rigor is present, death occurred under 3 hours before. If the body feels warm and stiff, death occurred 3-8 hours earlier. If the body feels cold and stiff, death occurred 8-36 hours earlier. If the body is cold and not stiff, death occurred more than 36 hours earlier.
You can find more information here
Forensic pathologists are essentially required to estimate the time since death (TSD) to assist in death investigation by limiting the investigation period and thus helping narrow down the number of suspects in homicide cases. TSD also provides valuable information in establishing the timeline...
www.ncbi.nlm.nih.gov