Was it merely coincidence or something sinister that a man's head was found behind a Dania Beach auto parts store named Millions of Parts?

The question is part of a grisly mystery that now covers two counties, as authorities in Miami-Dade try to determine whether that head and a torso discovered in a Miami Gardens canal the day after Thanksgiving belong to the same victim.

Police still don't know his name, let alone who killed him, or why.

"To dismember someone is really...