SAN JOSE — Two people killed in separate shootings over the weekend have been identified by authorities and investigators suspect gang motives in one of the slayings, according to the San Jose Police Department.

The pair of killings were part of a violent three-day stretch that also saw two shootings in unincorporated San Jose, including one where Santa Clara County Sheriff’s deputies shot and killed a woman reportedly wielding a knife.

San Jose police and witnesses said Pedro Meza Hernandez, 20, of San Jose, was shot in the head Friday evening while driving a pickup truck near a shopping center at West San Carlos Street and Leigh Avenue. Officer Albert Morales said Hernandez was involved in a “disturbance” with the occupants of another vehicle when shots rang out.

The gunfire sent shoppers scrambling for safety, and when they got out from cover they saw Hernandez slumped over inside his truck, which crashed into a parked car, bullet holes visible in the windshield.

Morales said investigators suspect that shooting was gang related, but declined to comment further. No suspects have been identified.

About five hours later and just as many blocks away, three deputies from the Santa Clara County Sheriff’s Office were called to a home near Cleveland and Olive avenues. In an apparently chaotic scene, they encountered a woman holding a knife and shot and killed her when she reportedly defied their orders to drop the weapon.

The Sheriff’s Office did not release any more details Monday, including the identity of the woman killed. The deputies who opened fire have been placed on administrative leave pending an investigation monitored by the District Attorney’s Office.

Sunday morning around 3 a.m., San Jose police were called to a home in the 100 block of Goldenrain Drive in the Edenvale neighborhood, where they found 19-year-old Tony Hoang outside suffering from a gunshot wound. He died there.

Morales said Hoang was in an argument with someone he knew. The person suspected of shooting him was still being sought as of Monday afternoon. Police have ruled out gang motives in that shooting.

The weekend was preceded by the investigation of a deadly Thursday night shooting in the parking lot of a taqueria in the 800 block of South White Road, in an unincorporated pocket of the city. The identity of the male victim in that case has not been released.

All told, San Jose has recorded 43 homicides this year, a total that includes a homicide investigated by San Jose State police not counted by SJPD. Three homicides have been recorded in unincorporated parts of the city, which are investigated by the sheriff’s office.

Anyone with information about the San Carlos and Goldenrain shootings can contact San Jose police at 408-277-5283. Information about the deputy-involved shooting or the taqueria killing can contact the Sheriff’s Office at 408-808-4431.

Contact Robert Salonga at 408-920-5002. Follow him at Twitter.com/robertsalonga.