San Bernardino County Sheriff's deputies were called out to a home in the 9000 block of Marcy Road about 2 a.m. and found a Black Bear fatally shot.
Authorities believe the cub was at least a year old because it was over 80 pounds.
The homeowner told deputies that he was forced to shoot the bear out of concern for his friend, who was outside when the yearling and two other bears approached. The bears were apparently rummaging through trash in the back of a pickup truck.
Deputies confiscated the rifle and turned over the investigation to the Department of Fish and Game.
The shooting has outraged residents, who say part of living in the forest community is dealing with the bears.
Tom McIntosh of Gilmore Real Estate said the trash should never have been left out in the first place.
"We are hoping that in some way, he can justify what he did because it's a terrible thing," said Antoinette Hason of Forest Falls.
Hason said residents see bears all the time.
"They're slow, lumbering animals," she said. "They're no threat."
Authorities said there was a female bear and another yearling with the cub that was shot. They managed to escape.
The homeowner is expected to face charges. The warden will likely file charges of an unlawful take of a bear and violating a county ordinance on trash storage.