Factual error: Crew members aboard the spaceship at the planet Mars are shown in instant communication with Earth. Because of the distance, a few minutes must pass each time before communication is made (between 10 and 22 minutes depending on where the planets are in their orbits, and that's each way so at least 20 minutes from when you say something until you hear what they say back).
Plot hole: The rape scene in the parking lot... there is no one around for THAT long? But wait, once the detectives come in the scene two people are walking in the background with a shopping cart - they must have seen something!
Trivia: An early concept for the film was to make a more direct follow-up to the original's climax, where we see a rat become infected by the alien DNA. The film would have revolved around an army of alien-rat hybrid monsters that must be exterminated. This idea was eventually dropped in favor of a different script.TedStixon