1. A method for determining whether a first product has been successfully purchased at a check-out register including a product purchase scanner, the method comprising the steps of: a computer identifying in a video record a first movement of a first product adjacent to a scanner and an approximate time at which the first product was moved adjacent to the scanner; the computer determining that the scanner did not record a purchase transaction within a predetermined time of the time at which the first product was moved adjacent to the scanner as identified in the video record; the computer measuring a difference in time between the time of the first movement of the first product adjacent to the scanner and a time of a second movement of a second product adjacent to the scanner; and a support vector machine, that has been trained with a training video record that depicts a plurality of movements of products adjacent to one or more scanners, determining a likelihood that the first product was successfully purchased based in part on the difference in time.