The suicide in 18 inches of water theory doesn't make any sense.
Look at waterboarding, for example. You have Muslim fighters who drive suicide truck bombs, wear suicide bomb vests, participate in airplane highjacking/crashing suicide missions, and so on. Yet, these same type of guys fold like a cheap tent when they're being waterboarded. I read somewhere that Khalid Sheikh Mohamed went 2.5 minutes before cracking and that was supposedly much, much longer than most people can go.
The point being that even people who aren't afraid of committing suicide can't cope with being underwater long enough to actually drown. Maybe jumping off a bridge into a lake or jumping off the side of a cruise ship into the ocean would be effective since after you jump, you're past the point of no return before you even hit the water. But nobody is going to be able to kill themself in 18 inches of water!
It looks like her body was found not far from I-95. Is there a possibility that a car pulled to the shoulder in the middle of the night when there was no traffic and dumped her into the water from the overpass?[/QUOTE]