The Police Department's METRO unit will add 12 extra officers to its 17 officers on duty Friday and Saturday and 24 METRO officers will be on patrol Sunday, police spokesman Sgt. Jason Dwyer said.
The department's MERGE unit is sending 12 officers out on patrol Friday, eight on Saturday and 10 on Sunday, Dwyer said.
Officers from the gang suppression detail, working overtime, are also being deployed this weekend to known gang hot spots in the city, Dwyer said.
In addition, regular patrol officers on assignment "have been directed to focus any free patrol time on known gang neighborhoods in their beats in an effort to provide a high level of visibility," Dwyer said in a statement.
The department's moves come in the wake of four violent deaths in the city since last Sunday that brought San Jose's homicide total to 20 so far this year.
Police do not know if any of the murders resulted from gang activity but the department's "proactive efforts are in response to a general concern about further violence," Dwyer said.
The METRO unit is a rapid response program with officers sent to aggressively attack areas of the city affected by crime, especially gang-related crime and narcotics, according to the department's website.
MERGE, known as the Mobile Emergency Response Group, is a SWAT team with special skills in weaponry and other equipment and works in uniforms or covertly in plainclothes and unmarked cars.
There is no information about suspects in any of the four killings. All of the victims were young males shot to death, police said.
The most recent homicide came early Thursday, when police answered a call at 5:21 a.m. from neighbors hearing gunshots and screaming at the intersection of Santee and Audubon drives in East San Jose.
The young male victim died on the northeast corner of the intersection near Santee Elementary School, which school officials later that morning ordered closed for the day.
Police have not released the identity of the man, who was reported to be 19 or 20 years old.
At about 6:30 p.m. Sunday, Christian Comilang, 15, and Johnson Cular, 16, high school students who were friends since elementary school, were gunned down in the 300 block of Caribe Way off of Rhinehart Drive in East San Jose.
Cular died at the scene and Comilang died shortly afterward at a hospital.
Later that night at about 10:10 p.m., 20-year-old San Jose resident Justin Watkins was shot while in the 100 block of Hayes Avenue in South San Jose and was pronounced dead about 15 minutes later.