If I had just slaughtered someone, and was carrying a bloody corpse in a wheeled bag through the streets, the LAST place I'd head would be anywhere near Union Turnpike or the Jackie Robinson Parkway. As someone above posted, those are two heavily traversed highways. At 4:30 AM there would be plenty of traffic. People are going to an early work shift, coming home from a late work shift, coming home from a night on the town, or a dozen other scenarios. The killer also risked being run over. The Interboro (Jackie Robinson) is a twisty-turny highway that's a pain to drive, and if the killer crossed the parkway on foot, wearing dark clothing, he/she risked becoming a casualty.
There have to be at least 50 home or business cameras that caught these images, beyond the one we've seen.