If it was a random murder you should be fine, however they will still be able to discern time of death and cause of death and thus giving them a general idea of the murder weapon. They would also be able to identify the body either through facial recognition or if you're lucky and the body has decayed enough for that to be impossible (unlikely since the sewer will clog but ya never know) they can still identify them via dental records or by cross-referencing missing people.I Stomp on Kittens said:If that were the case how much evidence could they actually get from that body? I'm no sewer expert but wouldn't it be covered in everybody's stuff? You might be fine unless they had some reason to suspect you or you have some tie to the person. Right?
So yeah they can get quite a lot, not to mention unless they find evidence pointing otherwise, they know you're in the general region.