Heavily armed officers surrounded a house in Long Island after police received a call from a person claiming to have killed his mother and brother.
Officers broke in and detained a 17-year-old boy.
It turns out the whole thing was a prank, pulled off by someone playing the video game "Call of Duty" with that boy online.
Police say the boy had reportedly beaten his opponent in the game and the opponent called the police.
"Swatting are hoax calls, calling out SWAT teams to make believe, typically hostage barricades, murder situations," said ABC News crime and terrorist analyst Brad Garrett.
"It's a real problem for law enforcement," said Michael Tangney with the Long Beach Police Department. "They actually have a system, I believe, where they get points for the type of tactical response the police get, if helicopters are involved, the SWAT team, controlled entry."
Investigators confiscated the boy's video game system and hope to track down the person who called in the phony threat.