The incident happened in the 2400 block of Foothill Boulevard around 3:20 a.m. after authorities received a report of a family disturbance.
When the officers arrived, they were confronted by a man who had an unknown dark object in his hand. One officer believed the object was a weapon and ordered the man to drop the item, but he did not comply with commands.
The man continued to approach the officer, who feared for his safety and fired one round at the suspect. After firing the round, the officer discovered the object was not a weapon, but the man continued to approach the officer in a "threatening manner," according to a press release.
The officer then tried his Taser on the man, but it did not work, authorities said. The suspect continued to move toward the officer despite being ordered to stop.
At some point, the man then reached toward the back of his waistband and made a "threatening statement," which caused the officer to believe the man was arming himself, authorities said. He then fired several rounds at the man, striking him in his upper body area and also shooting an officer who was assisting in the incident.
The officer, who was shot in the lower torso area, along with the suspect were taken to a hospital for treatment. The officer suffered non-life-threatening injuries, authorities said. The man was in stable condition.
Authorities said it is still unclear if the man was actually armed during the incident.
The investigation was ongoing.