Etienne is a (presumably French) scientist living in Africa, who is studying the legendary Mokele-mbembe. He is leaving a photo development lab in the city during a parade of some sort, when he makes the mistake of taking a shortcut through an alley and finds himself waylaid by Dr. Eric Kiviat, who proceeds to jam a knife into his stomach.
Etienne collapses onto a pile of cardboard boxes whilst Eric absconds with the folder containing the photographs the other scientist had just gotten developed, containing some blurry shots of the Mokele-mbembe itself - a living brontosaurus!
Precisely who Etienne was to Eric, and why Eric felt the need to murder him for the photos, is never explained. Only a single line of dialogue later on even reveals the poor bastard's name and alludes to some kind of professional relationship between him and Eric.
All signs point to Etienne being a rival of Eric's, but still, the movie could've been a little clearer considering it is Etienne's rather graphic (for what is ostensibly a kid's movie) murder within the film's first five minutes.