1. A method for security and/or automation, comprising: detecting a presence of a person at a location; determining a first identification datum associated with the person; calculating a first probability of identification at a first node in a decision tree based at least in part on the first identification datum; determining, based at least in part on the first probability of identification, a second identification datum associated with the person; calculating a second probability of identification at a second node in the decision tree based at least in part on the first probability of identification and the second identification datum, the second node dependent on the first node; determining an identity of the person based at least in part on the second probability at the second node in the decision tree; and initiating an action based at least in part on the determined the identity of the person.