Here's a live look at the shooting scene on Rutherford Lane, that's near the Highway 4, I-680 interchange.
So far, investigators have revealed that deputies responded to a call at the home around 8:40 p.m. They say they encountered a man holding a knife they say he wouldn't put down, despite repeated warnings. One deputy then fired at him.
"At some point, that man approached the deputies in a threatening manner and despite repeated warnings to put down the knife, he continued to approach the deputy who for his own safety discharged his weapon and struck the suspect several times," said Contra Costa Sheriff's spokesman Jimmy Lee.
The victim is a 46-year-old man. The sheriff's office hasn't said why they were called to the house in the first place.