UPDATE: The search for the mountain lion was called off Thursday after a massive 28-hour search turned up no signs of the animal.
"They said the mountain lion was three times as big as my dog, and that's scary," said dog owner Jonathan Slater.
Officers with Fontana police and the Department of Fish and Wildlife received word of the attack and arrived at the 4100 block of Fox Borough Drive at approximately 3:30 a.m. Wednesday. The incident occurred in the backyard of a home in the northern part of the Hunter's Ridge neighborhood.
Slater's father heard the dog, named Princess, in distress and went outside. That's when he found a large mountain lion standing over his deceased dog. He said the lion displayed very aggressive behavior toward him.
Fontana police arrived to find the mountain lion in the front yard. They shot at the lion to scare it into the canyon. However, officers said the lion kept returning and coming toward the officers in front of the home a total of four times before disappearing into the canyon.
"The advice that we had is the behavior of this animal is very, very bizarre and very unique, and what they told us is this animal is a significant public threat," said Fontana Police Chief Rod Jones.
Officials say there was no evidence that the lion was ever struck by any rounds.
Fontana police have deemed the mountain lion an imminent threat and are actively trying to track down the animal using extra resources at their disposal. Armed officers are patrolling the foothills, and a helicopter equipped with heat-seeking equipment is also searching.
Residents are encouraged to remain vigilant, keep their pets indoors and dial 911 if they spot the lion in their neighborhood.