Naperville police Cmdr. Lou Cammiso said Willson at 10 a.m. July 10, 2014, placed "possibly a computer-generated 911 call." The caller was "advising police of a hostage situation" in a house in the 2800 block of White Thorn Circle, "with explosives rigged (throughout the home) by someone who had just shot their girlfriend with an AR-15" assault rifle, Cammiso said Tuesday.