Only issue I have here, is why would they go to the trouble to fake someones death and not scrub the cameras nearby when it happened?
I'm assuming that "fake someone's death" was just poor wording....the dude definitely died.
As to your question, they did this, if it wasn't actually an accident, in an attempt to make it look like an accident. Confiscating all the local security camera footage would be highly suspicious. You know, like they did on 9/11 and the Pentagon.