① cooling

With the passage of time after death, the body temperature will continue to drop. Eventually it becomes the same as the surrounding temperature. The hourly decrease is 1 degree in winter, 0.5 degree in summer and 0.7 degree in spring and autumn. However, when it drops to about 25 degrees, its cooling rate will become slower. The cooling rate of fat people and thin people is also slightly different.

② Death point

There are countless blood vessels flowing in the human body, so the blood flow stops after death. The blood that stopped flowing soon appeared red and purple spots on the skin of the lower part of the body because of the gravity on the earth. Judging from the appearance of the lividity, we can know the approximate time of death.

③ Hardness

As time goes on, the body will become hard bit by bit.

④ Rot

After the corpse stopped being stiff, it gradually began to rot and stink, with its internal organs protruding, and then rotted and disappeared, leaving only bones. However, due to different symptoms, the rate of decay varies greatly. Factories exposed to air rot fastest. The factory corpse in the water is twice as slow as it is, and the corpse buried in the ground is eight times slower than it. And there are often mosquitoes and flies breeding on the bodies. So judging from the size and meters of these larvae, we can also infer the time of human death.