Perfect crime, no real such thing but heres a way for someone to commit a hit, murder and make it possibly perfect.
Get involved with waste management in some capacity.
After the deed is done, well the body is not sent into the recycling bin, but the garbage bin, Into the garbage truck to the landfill(best bet is to chop up the body and bag it separately) Ok once the body and parts are properly disposed of in the landfill and buried it is next to impossible to find as ponce that shit is buried it ain't environmentally friendly to dig up landfill once it has been sitting there due to toxic wastes, gases etc.
So joe blow just disappeared, left town whatever.
Where the perfect part goes out the window is if between the killing and the landfill burying the body is somehow found.
THere was a case in Montreal I believe years ago where they suspected a guy had been murdered and buried in a landfill but they could not prove it because it was too dangerous to dig up to find out.
Other then that take a boat ride and dump it in the ocean(never a lake) with a good weight set to go along with the body and the rest takes care of itself.