Police responded to a home in southern Riverside Monday in connection with a murder-suicide in San Bernardino that left two adults and one elementary school student dead and another student critically wounded.
Video from the scene of the search showed San Bernardino Police Department SWAT officers responding to the home in the 19000 block of Mount Wasatch Drive on Monday afternoon.
A police source confirmed to KTLA that the response was connected to the investigation into the shooting at North Park Elementary School.
A gunman walked onto the campus, checked in the main office using an ID, and proceeded to a classroom, where he fatally shot a teacher, authorities said. The gunman then killed himself.
The shooter was identified as Cedric Anderson, 53; his adult victim was Karen Smith, also 53, his estranged wife of just a few months.
Two students were hospitalized in critical condition. They were not targeted but were near the teacher, police said. One of the students, 8-year-old Jonathan Martinez, later died at Loma Linda University Medical Center. The other student, a 9-year-old, was listed in stable condition.
A BMW that was surrounded by crime scene tape in the North Park Elementary School parking lot is registered to Smith, whose name is linked in property records to Mount Wasatch Drive address.
Two vehicles registered to Anderson were left parked at the home.
Neighbor Tony Holmquist, who knew the couple, watched the raid.
"Now we're just fearing for the family," Holmquist said.
The Los Angeles Times reported that the Anderson and Smith knew each other for four years before getting married in January. They moved into Smith's home in Riverside, Smith's mother Irma Sykes told the Times.
Police said the Riverside home was secured to confirm there were no additional victims inside. A search warrant had not been served on the home as of early afternoon, San Bernardino police Chief Jarrod Burguan said. Another home in elsewhere in Southern California was secured as well, he said.
KTLA's Jennifer Thang and Olsen Ebright contributed to this article.