Some weapons are designed for panicfire, i.e. they have overly heavy and long trigger pulls. This disrupts aimed fire, or the ability to hit targets at range, but when in a panic situation people are more likely to pull hard and long on the trigger, which would disrupt weapons with medium trigger weights.
Most pistol fights happen at ranges less than seven metres, meaning that for self-defense, pistols do not necessarily have to be accurate beyond this range. However, many police forces rate pistols at twenty-one feet (seven meters), the distance that the average criminal armed with a knife can run before a police officer can draw and fire. (This is called the Tueller Drill.)