The woman was hit at the intersection of Madison and Emerald streets just before 8 a.m. Sunday. Police said the woman, identified as Isabel Pablo Tomas, started to cross as the officer was driving through the intersection in his marked police car.
According to officials, the officer, who was not hurt, was responding to a call. The officer and another police unit both stopped to help the victim.
Tomas, 58, died from her injuries Sunday night at the hospital.
Traffic investigators with the Riverside Police Department spent the day marking the road and collecting evidence. Part of the investigation will look into whether Tomas was inside or outside the crosswalk. Despite repeated requests, the police department has not released information about the incident or the officer involved.
Witnesses said the officer did not appear to have his siren or lights on as he went through the intersection.
Angel Gaytan said he was standing in his front yard and witnessed the accident.
"I heard the brakes, looked over and the cruiser hit a lady crossing the street," he said, adding that the impact threw Tomas to the other side of the intersection.
Pedro Tomas, a son of the victim, owns a store down the street. He said he and his siblings never got the chance to celebrate Mother's Day with her.
"I'm hurt, my brothers, the four of us. But nothing we can do about it," he said.
Pedro Tomas said he and his siblings accept it as a mistake.
"He's just a human being. Anyone can make a mistake," he said.
The body of the victim, who was enjoying her golden years in the United States, will be taken back to her native Guatemala for burial, Tomas said.