When you kill someone in Death Stranding, you must dispose of the body before it goes necro. If you have progressed passed the first hour or so of the game, you will know exactly what this means. The body will essentially explode in an event known as a voidout. This is why bodies can’t be left lying around.
Dealing with dead bodies is easy enough, you need to take them to an incinerator before they detonate. There are a few incinerators in the game so you shouldn’t have to go through any excess stress in order to bring a body to one.
Faster way to dispose of dead bodies
Purely by accident, I discovered a much faster way to dispose of dead bodies in this game. When you have a dead body, wrap it up in a body bag and head to the nearest knot city. Bring the body down into the delivery area and offload it in the corner somewhere. You will see a warning flashing above the body. Head down into your private room and when you wake up the body will be disposed of.
This disposal will cost you 400 likes but what point do these even have anyway. A small cost of 400 likes is not much to save you the long ass journey to an incinerator to deal with this.
If you are curious about what happens, I have made a video where I spend some time trying to trigger a voidout.