CNN has obtained an email dated January 6 that was sent hours after the shooting at Fort Lauderdale-Hollywood International Airport, saying the policy is "effective immediately" for the aviation police.
The email from Lt. Anthony Bates, which has the subject line "Landside Disturbances," says "APD will NOT be dispatched to any disturbances on the 'landside' (unsecured side) of ORD," a reference to O'Hare International Airport.
It says the officers "WILL continue to be assigned disturbance calls, along with CPD (Chicago Police Department) to all 'airside' (secure side) areas of the airport."
The secure side is after Transportation Security Administration checkpoints.
The Chicago directive follows Friday's shooting in the baggage claim area
of the Fort Lauderdale airport, which left five dead. Esteban Santiago, 26, could face the death penalty
in connection with the shooting.
Armed police quickly responded to the shooting and took Santiago into custody.
In Chicago, about 300 unarmed aviation police officers patrol O'Hare and Midway airports. More than 200 armed Chicago police, the primary law enforcement agency at the two airports, are also assigned at both facilities.
Both Chicago police and airport officials have repeatedly said the airports are sufficiently staffed and defend the multilayered security system.
But aviation police officers told CNN the new rule was absurd.
"This is in response to what happened in Florida," said an aviation police officer who asked not be identified. "Instead of doing the right thing, they are basically telling officers don't look for any trouble, just walk away. Officers are shocked by this."
In Chicago this week, the unarmed aviation police officers were still patrolling the baggage claim, passenger check-in areas and other public locations before the TSA checkpoints.
A CNN investigation revealed that, not only are the aviation police officers unarmed, they are also instructed to "run and hide"
in the event of an active shooter. Officers have told CNN the policy puts them in danger.
The investigation found that Chicago was the only city with major airports being patrolled by unarmed police officers.
Efforts to change that long-standing airport policy have not been successful.
Last April, Alderman Chris Taliaferro introduced an ordinance
that would arm the aviation police officers, but it still has not received a hearing.
Taliaferro said this week he has not withdrawn the ordinance.
"We are putting these guys' lives in danger, and we are risking safety and harm to residents who use the airport," Taliaferro said. "I think Chicago has gotten complacent that we are adequately secure."
CNN has not received a response for comment from Chicago airport officials or the mayor's office about the new directive.