The stabbings happened at 2:11 am in a home in East San Jose at Tehama Avenue and Daytona Drive.
"Everyone lives together at this residence. We knew who he was, we knew what vehicle he was driving. We were able to put out a be on the lookout (alert) to allied agencies in the area," Sgt. Christina Camarillo said at a 10:00 am press conference.
The victims, two women, and one man survived, suffering mild to moderate injuries.
Police located the suspect's car, saying it was abandoned near Highway 85.
"Shortly after that, after 5:00 am, we get a call from the CHP about the pedestrian fatality they had on 85. We quickly connected the dots and were able to confirm that the pedestrian that died was our suspect for the multiple stabbings. The investigation is still ongoing. We don't know what precipitated or what motivated this individual to commit these stabbings. We were in the process of obtaining an arrest warrant for him for attempted murder for this incident. Obviously, a very tragic sequence of events this morning," said Sgt. Camarillo.
Sgt. Camarillo could not say whether the man died by suicide, referring all questions about the car hitting the man to the CHP.
The CHP has not returned our call.
Police have not released information about the man who died or his relation to the stabbing victims, saying the investigation is still ongoing.