Deputy Crystal Hernandez tells City News Service that bystanders reported a man was running in and out of traffic, waving a spear at people Thursday night in Santa Clarita.
He was confronted by deputies after he struck a passing vehicle with the implement.
Deputies opened fire but the suspect appeared unscathed and continued to behave erratically.
Hernandez says the man then approached deputies with a knife. Deputies fired again with multiple rounds striking him in the upper torso, according to Hernandez.
The suspect, who was not named, died at the scene.
No deputies were hurt.
The incident is under investigation.