Viggo Mortensen claims that, prior to shooting their scene together, Christopher Walken ate several whole garlic cloves.
The film was originally filmed in 1993 and released two years later in 1995. This was the Weinstein's M.O., as they would film a movie before editing them, reediting them, and finally releasing them a year or two later.
The writer/director is also the writer for the original Highlander film in 1986. Similar themes can be found between the two movies. Immortals at war for centuries, they wear trench coats, and both stories begin near the climax of the much longer history of the characters.
Colonel Arnold Hawthorne is played by Patrick McAllister. Due to the nature of his role and the long gap after It's Alive (1974), McAllister is not credited, but he appears as "special thanks" for his collaboration in the movie, credited as Patrick Kerlee McAllister.
Gabriel tries checking all the school kids to see if he can find if they've had Hawthorne's soul stuffed into them. As part of doing so he lets a couple of them blow on a horn he has, (Gabriel blowing his horn is supposed to be the sign of the end of the world) but cautions to do so very carefully, and just a little bit at a time.