Piotr Holy, of the 1100 block of Brockway Street, admitted to authorities that he killed the dog, Willy, and had mistaken it for a coyote, according to the Palatine Police Department.
Holy had set up an elaborate trap for coyotes, rigging a deer carcass with a motion sensor and an alarm device, according to police.
Willy's owner Monica Gliga was trying to leash him in her backyard when police say he got away from her. When Willy ran into Holy's yard setting off the motion sensor, Holy fired a single shot from .22 caliber rifle, according to authorities.
Willy was found shot by Gliga and he died during surgery in an animal hospital, police said.
"It is a scary thought people have guns are willing to use them to shoot random things in the neighborhood,"neighbor Rao Addepalli said.
Willy was an important part of the Gliga family. Gliga tells ABC7 News that she got the dog nearly nine years ago when he was just a few months old.
She raised him, loved him and now mourns him.
The incident unsettled nearby residents.
"Pretty scary from any angle you think about it," neighbor Jay Puttappa said. "Because this seems to be a quiet neighborhood, they have professionals and affluent. Pretty concerned about what can go wrong in this neighborhood."
Holy, 40, is charged with aggravated cruelty to an animal, obstructing a police officer, reckless conduct and unlawful discharge of a firearm. He is expected to appear in bond court Thursday.