The incident happened on the 200 block of North McPherrin Avenue at about 12:20 a.m. Wednesday.
Officials said police got a call from a man saying his brother was threatening their mother with a knife. When authorities arrived, they said there was a dispute going on between a man and a woman.
Officers had to kick open the door of the bedroom, and according to Lt. Dave Coleman of the Los Angeles County Sheriff's Department, the suspect lunged at them with a large knife.
One officer shot the suspect. No one else was injured.
The sheriff's department is investigating the shooting.