Monica Quan, 28, and Keith Lawrence, 27, were found slain Sunday night in Lawrence's car parked on the top floor of a parking building at their Irvine residence, the Ventura County Star reported.
Police said the deaths were being investigated as a double homicide. No arrests had been made.
"The loss of any member of the Titan family causes our community great grief, but the loss of one of our own under these circumstances is indeed tragic and heart wrenching," Cal State Fullerton President Mildred Garcia said in a statement. "We hope that Monica's family and friends will feel and be comforted by our support during this difficult time."
The Orange County Register reported the couple had recently moved to the area.
A police spokeswoman said it appeared the couple, who were found shortly after 9 p.m., had been dead for some time.
"It doesn't appear they were robbed," Lt. Julia Engen of the Irvine Police Department said. "There's no obvious motive."
Lawrence and Quan were graduates of Concordia University and had played for the school's basketball teams.