A computing system obtains a first category for a first motion event. The system sends a first alert indicative of the first category to a user. After sending the first alert, it obtains a second category for a second motion event. In accordance with a determination that the second category is the same as the first category, the system determines whether a third motion event of the first category has been detected in a preceding predetermined amount of time before the second motion event. If the third motion event has not been detected in the preceding predetermined amount of time before the second motion event, the system sends a second alert associated with the second motion event indicative of the first category to the user. If the third motion event has been detected in the preceding predetermined amount of time before the second motion event, the system forgoes sending the second alert.