An ABC7 I-Team Investigation
CHICAGO (WLS) -- It may be a prank, but it isn't funny - and can be deadly.
"Swatting" is a fake call to 911, aimed at drawing a full-fledged response by police Special Weapons and Tactics Teams to an address where there is no actual emergency.
It is an extreme practical joke that happens 400 times each year in various U.S. locations. Wednesday's incident at Northwestern University in Evanston was the latest swatting incident.
The apparent goal of such prank callers is to surprise unwitting victims with a frontal police response right at their doorsteps. Hollywood celebrities including Ashton Kutcher and Justin Bieber have fallen victim to swatters, but the stunt is most popular among video gamers and used as a form of revenge.
"Not to the best of my recollection have we dealt with a hoax of this level before," Evanston Police Commander Ryan Glew said following Wednesday's incident on Chicago's North Shore.
When elite, heavily-armed police units respond to supposedly active crime scenes, it isn't just inconvenient and costly - it can be downright dangerous and deadly.
"Oh my God! He's pointing it right at me! I've got my hands up!" said an innocent New Mexico woman in 2014 when police there put her at gunpoint after a swatting call.
Also in 2014, New York police stormed unsuspecting Long Island homeowners after someone angry about losing a video game reported an armed man was inside.
Sometimes the situations don't end well.
Last December in Wichita, Kansas police received a 911 call in which a man said: "They were arguing and I shot him in the head, and he's not breathing anymore. I already poured gasoline all over the house. I might just set it on fire."
When Wichita police arrived at the hoax address, the homeowner answered the door and was shot by police and killed. He was an innocent victim who had apparently spooked responding officers by reaching toward his waistband.
A 25-year-old man made the swatting call from Los Angeles, apparently after an online quarrel, according to Kansas police.
In Evanston, the nation's latest swatting call became a critical situation for police.
Commander Glew called it "very dangerous any time that you have a response, that people, officers that are armed coming to what they believe is an active shooter or somebody who has been shot."
There is a fairly new Illinois state law that gives courts the authority to require that swatting pranksters reimburse police for emergency response costs. But federal anti-swatting legislation failed in 2015 and new legislation introduced last year in Washington is still being considered.