The officers had been called to the Kansas City home after an alligator sighting had been reported by a member of the public.
And when they saw the powerful-jawed creature lurking in the grass, they were quick to reach for their rife and shoot it twice in the head.
It was only when the second shot bounced of the stationary creature the officers realised it was made out of concrete and a garden ornament.
Homeowner Rick Sheridan said the 'reptile' was there to keep people off his land… maybe a creepy gnome would have been better.