The problem with cop-writers is that they all hold back the good stuff. They only tell the real stuff for other pigs.
It is time to break up that information cartel. This will be a short but dense post.
For any chemical you can name, 4 things accelerate decompositon:
2) UV rays (sunlight)
3) Moisture (bacterial growth)
We can model the human body as a very large molecule. There are tradeoffs everywhere in disposing of a body.
The fastest way for a body to decompose is to sit out in the nice hot sun, where it is humid out. But that draws attention. Not only will animals scavenge it, but it will stink.
Criminals sometimes dig graves or throw bodies into the ocean. But that reduces UV rays, cools the temperature and reduces oxygen, which preserve the body. A buried or submerged body takes much longer to decompose than a body on the surface.
One has to make the calculation: how fast to decompose? What is the probability of discovery? Then act accordingly. In general the most rarely discovered bodies are dug deep in remote rural areas or dumped into cold deep bodies of water.
…and now for the other side, by symmetry.
So, the call comes in that someone found a body. How to ID it?
First, we’d start by looking at the vic’s clothes. We’d check their wallet or purse for their driver’s licence, student ID, receipts, and so on. Maybe we’d look at the clothes or something special about the earings. That’s the easy way.
Sometimes, the killer took the clothes and IDs. Then forensics is necessary. With everything below, we need a known to compare the unknown to. That may come from a missing persons database.
Forensic odontology is looking at the teeth. Everyone’s teeth are a little different. We can match an unknown body’s teeth with a known sample from a dentist’s xrays.
DNA can be taken from the hair, skin, muscle, pulp tissue in the teeth, or red pulp tissue in long bones. This can be compared to a known sample.
Prints can be taken if there is skin on the palms or fingers. Again, one just has to match it up with a known sample.
Sometimes, there is no DNA, prints or teeth. Forensic anthrolpology can be used on the bones. Each race has a characteristic tissue depth. The ridges and bones of the skull can reveal race.
Bring in a skull, and a skilled practitioner can build the face. This takes a terrific skill.