Carrie Thomas, 23, was outside a drive-up ATM just before midnight behind the Visterra Credit Union at Cactus Avenue and Graham Street.
She had just gotten off work at Shakey's pizza, where she was a manager.
"She was very easy to talk to," said the victim's friend, Ashlee List. "She was older than me, so she was like a sister. If I had any questions about anything, she was always someone I could go talk to."
When the call came in, deputies responded to what they thought was a routine traffic collision but found Thomas inside her car.
Thomas was taken to the hospital, where she was pronounced dead from a gunshot wound.
"Robbery may be a motive and that's what we're looking at now, but it's not clear at this point," said Sgt. Joe Borja of the Riverside County Sheriff's Department.
"Surveillance video can make the world of difference," he said. "Depending on what we actually receive, it could help us solve the crime."
A statement was released on behalf of Thomas' family.
"The world just lost a wonderful person, but we know that she is watching over us. We all loved her and she loved us with nothing less than her whole heart," the statement said.
Anyone with information is urged to call Moreno Valley police at (951) 486-6700.
A memorial fund was set up for Thomas.
Donations can be dropped off or mailed to:
Visterra Credit Union
PO Box 9500
Moreno Valley, CA 92552-9550
Attention: C. Thomas Memorial Fund
or send check by phone to (951) 656-4411