Variable Frame Rate During Critical Events

The reason I asked the question was because I have a DIY setup at home that includes integrated motion detection. Unfortunately, these domestic units have virtually no user options to adjuct frame rate. In my particular case (1fps). When the motion detection/recording function kicks in, the camera takes 6 consecutive frames and emails them to my iPhone. Unless the the intruder is a) dumb enough to stare at the camera as he enters frame - or b) stationary for the next 6 seconds. I get only one useful image. I wondered if commercial grade installations were designed to take into account that multiple images (generated at the moment of detection) would give a far greater opportunity to capture identification data?