Per
What we know about Delphi 'person of interest' (from 10/2):
Scanning Google maps, Rte 67 is very flat the entire length of Morgan county, and there are no significant bridges, except for over tiny creeks that aren't really livable. But the one over the White River you mentioned is on Rte 39, just 700 feet from the intersection with 67. That very well may be the bridge.
That's significant--he would have had to make it back to Morgan county within a day after the killing. It's feasible he could have done it by bike, but it would be an ambitious 90 mile trek over 7 or more hours. I don't think I'd be able to stand after that much riding.