Palo Alto police describe deadly officer-involved shooting

PALO ALTO, Calif. (KGO) -- Nineteen seconds. That's the time that authorities say elapsed from when Palo Alto police first confronted a man running at them with a knife and when they shot him to death.

According to police, on Christmas night the man was screaming and refused orders to drop the knife. Three officers moved away from the suspect and took cover behind their patrol cars.

VIDEO: Palo Alto police say suspect killed by officers called 911 to report false emergency

"And then all of a sudden with no warning, charged directly at our officers," said Lt. Zach Perron. "And it was only at that time when the suspect chose to force that confrontation that one of the officers deployed their Taser and the two other officers deployed their firearms."

Police say the man called 911 operators to report a phony crime in order to lure officers to the home that serves as a mental health treatment facility.