For three days earlier this month (Jan. 16 through Jan. 18), for a few hours each day, the Los Angeles County Fire and Sheriff's departments, in conjunction with the Claremont Police Department, conducted a large-scale Active Shooter training exercise in and around the immediate vicinity of Garrison Performing Arts Center on the Scripps College campus. The Claremont McKenna College campus was modestly affected by the practice drill, including noise from first-responder vehicles (police cars, fire trucks, ambulances, and helicopters), street closures, and impacts to common facilities and parking, due to blocked parking around the drill site. CMC also allowed two sheriff's helicopters to land and take off, intermittently, from CMC’s Parents Field, during mock medical evacuations. Although no one was actually air-lifted, sheriff's officers could be seen rappelling from the helicopters at the shooting site, shortly after 10 a.m. each day, once the converted military helicopters reached Garrison.
Although crews were on the scene each day in the early morning, peak drill hours were between 10 and 11:30 a.m., as nearly 20 fire engines, and numerous emergency response vehicles drove toward Garrison, using lights and sirens. Also on the scene were SWAT sharpshooters and SWAT personnel, who used blank rounds to simulate firing their weapons. In addition to giving agencies access to CMC's campus, a select number of the College's staff members volunteered to be victims in the drill, including members of the CMC search and rescue team.
The three-day drill allowed local law enforcement and emergency personnel to test their response and communications systems.