Start from the beginning.
1 - Under the bridge, looking out on the riverbed. Troy stands outside, looking uncomfortable and scared. Maybe have him purposefully looking anywhere but under the bridge to help hit this home (said bridge could also be used to help frame him in the panel). The actual body does not need to be visible.
TROY: Anything we can do to help?
2 - Under the bridge, Vanessa kneels near the body. She holds one arm, feeling for a pulse. She also looks uncomfortable and focuses her gaze down and away from the body itself. We still don't need to focus on the body, but maybe show it's battered to some extent (like on the arm, for example).
VAN: I think we're too late for that...
3 - Change angle to focus on where Vanessa is looking - there's a still somewhat fresh pool of blood next to the body. Vanessa looks horrified, maybe putting a hand to her mouth to keep from being sick. (This could also be reversed to a pseudo-worm's eye view from near the blood pool looking up at Vanessa's horrified reaction.)
VANESSA: But - oh, god! I think this happened recently!
TROY (off-panel): Van...
4 - Troy has come under the bridge, crouching to keep from bumping his head. He touches Vanessa's shoulder; she looks to him in response. He looks worried (being sure to focus on Vanessa and not the body); Vanessa still looks a little green around the gills.
TROY: Do you hear something?
5 - Under the bridge, looking out again (like in panel 1). A bad looking dude peeks around the corner, looking under the bridge itself. He looks suspicious (and mean). Maybe he has a busted nose (or some evidence of recent physical altercation).
6 - Switch angle to look underneath the bridge again. The body is there, but Troy and Vanessa are nowhere to be seen.