Continuity mistake: The opening narration says the season is late spring, or otherwise a warm season of the year in Arizona, yet many people are wearing wool suits, coats and long-sleeved shirts during the day. At one point, the sheriff's dialogue even discloses that it is 92 degrees (and no air conditioning).
Continuity mistake: Barbara Rush aims a death ray to the right and above of Carlson. The scene changes with Carlson ducking and now the ray is to the left of him at waist level. The ray hits the rocks behind Carlson for several seconds, but it doesn't start breaking the rocks up on the wall until Barbara swings the ray from left to right.