Police spokesman Jermaine Thomas said it is "out of the ordinary" for the city to have so much violence occur in such a short time frame. The three people were killed Saturday night and Sunday morning.
Arrests have been made in all three cases, but the names of the victim and suspect from a Saturday night shooting are being withheld pending further investigation.
"These incidents are definitely not connected," Thomas said. "The only common denominator is that there was alcohol involved," he added. All three cases involved people drinking at parties and then getting into fights, Thomas said.
Francisco Fernandez, 20, of San Jose was found suffering from multiple stab wounds in the 3400 block of Chapala Drive around 3 a.m. Sunday, Thomas said. He was pronounced dead at the scene.
Police arrested 22-year-old Marco Felix, also a San Jose resident, in connection with the murder, Thomas said.
Felix was booked into Santa Clara County jail.
At about 4:50 a.m. officers responded to a shooting in the 2700 block of Croft Drive.
Edwardo Alvarez, 21, of San Jose was found suffering from at least one gunshot wound. Alvarez was also pronounced dead.
San Jose resident Emmanuel Baca, 23, was arrested in connection with Alvarez's murder and booked into Santa Clara County jail.
Officers responded to a shooting in the 400 block of Sanders Avenue at about 10:20 p.m. Saturday and found a man about 25 years old suffering from gunshot wounds. The victim was taken to a local hospital where he died.
The suspect in that case was taken into custody Monday afternoon, Thomas said. Officers are investigating a few more details of the case, and the names of the suspect and victim are expected to be released later today.
The three murders bring San Jose's homicide total to 26 this year, Thomas said. There were only 18 at this point in 2007.