Donald Gennaro is a lawyer representing InGen's investors, who has come to Jurassic Park along with other experts to determine whether the park is safe (and profitable!).
"Your investors, whom I represent, are deeply concerned," he tells John Hammond. Of the other attending experts Alan Grant, Ellie Sattler and Ian Malcolm, he warns, "In forty-eight hours, if they're not convinced, I'm not convinced."
Hammond, confident that Jurassic Park is safe and will sufficiently wow Gennaro and the others, says, "In forty-eight hours I'll be accepting your apology."
Alas, it's probably Hammond who'll be apologizing to Gennaro in forty-eight hours. Or at least he would if Gennaro survived. The lawyer ends up going on the ill-fated first and only tour of Jurassic Park, which is conducted in garishly-painted electric Ford Explorers that run along a track. He ends up in the same vehicle as Hammond's grandchildren Tim and Lex, unwittingly becoming guardian by default since he's the only adult in the vehicle.
At first he seems up to the task, although perhaps a little impatient with the two (we get the impression Gennaro doesn't like kids). But it's when the tour is cut short by an approaching storm and everyone but Ellie Sattler is being taken back to the visitor's center that Gennaro starts proving to be a very poor guardian for Tim and Lex.
Unfortunately for them it is at this time that Dennis Nedry decides to steal the dinosaur embryos for rival company Biosyn, and to do this he must turn off the power. The Explorers stop. No one is to worried despite the fact they're alongside the Tyrannosaurus rex paddock.
Resounding footsteps shake the earth. and suddenly the Tyrannosaurus is there holding the fence. At this point the occupants of the Explorers realize that the fence isn't electrified anymore.
At this revelation, Gennaro freaks out and runs, abandoning the kids and hiding in a nearby bathroom. The Tyrannosaurus breaks out of her enclosure and begins to trash the car with the kids in it after being unwittingly attracted towards by Lex's flashlight.
In an attempt to save them, Alan Grant gets out and distracts the animal with a flare. Ian Malcolm follows his example and lights his own. However, instead of immediately throwing it to the side as Grant did, Malcolm rather foolishly keeps waving his flare which causes the Tyrannosaurus rex to charge right towards him.
Malcolm turns and runs towards the restroom, where Gennaro is hiding, apparently intending to join him in seeking refuge in the men's room. Crouching on the toilet inside, Gennaro can hear the footsteps and starts saying a desperate Hail Mary. But apparently prayers are being sent directly to God's voice mail because poor Gennaro is screwed. Either that or God just hates comic relief lawyers.
Malcolm bursts in but the dinosaur rams into the building, causing it to collapse all around Gennaro. Malcolm ends up buried alive in the rubble, while Gennaro survives relatively unharmed, the entire building collapsing around him, revealing him sitting there on the toilet.
Sitting on the toilet, trying to get the water out of his eyes and not sure what's going on, Gennaro just has time to register what is happening and give a pitiful "No, no!" when the Tyrannosaurus bites down, lifts him in the air, shakes him violently and promptly gobbles him up in a scene loved by millions of lawyer-hating moviegoers.
- In Michael Crichton's novel, Gennaro survives by dint of not being present during the T-rex's escape at all. Instead, it is InGen's publicist Ed Regis who abandons the kids, runs off, and later gets eaten. Gennaro the lawyer actually survives the entire book... only for Crichton to kill him off between novels by revealing in The Lost World he died of dysentery. Harsh.