The Pennsylvania Game Commission reported Tuesday that a wildlife conservation officer determined during a postmortem examination that the bear had been shot with a shotgun and a BB gun.
"There were hundreds of pellets from shotgun wounds under its skin," officer Chris Heil said in a statement.
While black bear hunting is legal in Pennsylvania, it is only allowed during fall and winter weeks as determined by the Game Commission, and all hunters must have proper permits and use approved types of guns or bows.
Cheryl Trewella, a Game Commission spokeswoman, said people "should not be shooting" at bears in residential neighborhoods, and that the type of pellet found in the bear's skin would not have been legal even for hunters to use.
"This is not the way people should be treating this bear at all," she said.
The decision to euthanize the bear last week stemmed from other injuries the bear sustained, including an old arrow wound in its back leg that may have been re-opened when the bear was clipped by a car, according to Heil.
Heil said it was "unfortunate that the story ended this way," but that the injuries made euthanization "a necessary outcome."
Authorities recommend people stay clear of bears spotted in residential areas and call police.