A computer-implemented process for identifying device detectors that are configured to detect a plurality of mobile electronic devices, the process comprising: detecting an alarm event at a monitored property based on an output from at least one sensor located at the monitored property; determining a location that is associated with the alarm event; identifying a device detector closest to or within a threshold distance of the determined location associated with the alarm event from a plurality of device detectors located within the monitored property; triggering the identified device detector to transmit, to the plurality of mobile devices at the monitored property, a request for responses: receiving the responses from the plurality of mobile electronic devices, comprising receiving, from the identified device detector, responses that the device detector received from mobile electronic devices at the monitored property; extracting electronic identifiers of the plurality of mobile electronic devices from the responses; and triggering an alarm response based on determined electronic identifiers of the plurality of mobile electronic devices, the triggering comprising i) obtaining a list of electronic identifiers for the plurality of mobile electronic devices known for the monitored property comprising accessing a stored list of known devices that are associated with the monitored property; ii) comparing determined electronic identifiers for the plurality of mobile electronic devices to the list of electronic identifiers; iii) for each non-matching electronic identifier, triggering an alarm response associated with unknown devices; iv) for each matching electronic identifier, identifying a user associated with the electronic identifier; and v) triggering an alarm response associated with the identified user. detecting an alarm event at a monitored property based on an output from at least one sensor located at the monitored property; determining a location that is associated with the alarm event; identifying a device detector closest to or within a threshold distance of the determined location associated with the alarm event from a plurality of device detectors located within the monitored property; triggering the identified device detector to transmit, to the plurality of mobile devices at the monitored property, a request for responses: receiving the responses from the plurality of mobile electronic devices, comprising receiving, from the identified device detector, responses that the device detector received from mobile electronic devices at the monitored property; extracting electronic identifiers of the plurality of mobile electronic devices from the responses; and triggering an alarm response based on determined electronic identifiers of the plurality of mobile electronic devices, the triggering comprising i) obtaining a list of electronic identifiers for the plurality of mobile electronic devices known for the monitored property comprising accessing a stored list of known devices that are associated with the monitored property; ii) comparing determined electronic identifiers for the plurality of mobile electronic devices to the list of electronic identifiers; iii) for each non-matching electronic identifier, triggering an alarm response associated with unknown devices; iv) for each matching electronic identifier, identifying a user associated with the electronic identifier; and v) triggering an alarm response associated with the identified user. receiving the responses from the plurality of mobile electronic devices, comprising receiving, from the identified device detector, responses that the device detector received from mobile electronic devices at the monitored property; extracting electronic identifiers of the plurality of mobile electronic devices from the responses; and triggering an alarm response based on determined electronic identifiers of the plurality of mobile electronic devices, the triggering comprising i) obtaining a list of electronic identifiers for the plurality of mobile electronic devices known for the monitored property comprising accessing a stored list of known devices that are associated with the monitored property; ii) comparing determined electronic identifiers for the plurality of mobile electronic devices to the list of electronic identifiers; iii) for each non-matching electronic identifier, triggering an alarm response associated with unknown devices; iv) for each matching electronic identifier, identifying a user associated with the electronic identifier; and v) triggering an alarm response associated with the identified user. i) obtaining a list of electronic identifiers for the plurality of mobile electronic devices known for the monitored property comprising accessing a stored list of known devices that are associated with the monitored property; ii) comparing determined electronic identifiers for the plurality of mobile electronic devices to the list of electronic identifiers; iii) for each non-matching electronic identifier, triggering an alarm response associated with unknown devices; iv) for each matching electronic identifier, identifying a user associated with the electronic identifier; and v) triggering an alarm response associated with the identified user.