Validating radio frequency identification (RFID) alarm event tags

An RFID portal of an EAS system first interrogates a first zone extending into a controlled area beyond a threshold distance from an interrogating antenna of the portal. The portal defines an exit from the controlled area, the threshold distance being less than a width of the exit. The portal first detects, in response to the first interrogating, a first response of a particular RFID tag. The portal second interrogate, subsequent to the first detecting, in a second zone extending into the controlled area at least to the threshold distance. The portal second detects, in response to the second interrogating, at least one second response of the particular RFID tag indicating a received signal strength of the second interrogating at the particular RFID tag corresponding to a distance from an interrogating antenna of the portal less than the threshold distance. The EAS system alarms in response to the second detecting.