Slain Irvine, California, Couple's Death a Mystery to Police

Feb. 5, 2013— -- The shooting death of a couple has mystified police in Irvine, Calif., with indications that they were shot by someone outside their car and were not robbed, police said today.

Monica Quan, 28, an assistant woman's basketball coach at Cal State Fullerton and her fiancé, Keith Lawrence, 27, a public safety officer at USC, were found dead in their car Saturday.

Lawrence was found slumped behind the wheel of his white Kia in the parking lot of their upscale apartment complex and Quan was found in the passenger seat. Both were shot by someone who was standing outside the vehicle, police said.

"Physical evidence at the scene leads us to believe it was not murder/suicide. Their personal effects did not appear to be disturbed. Therefore, no obvious signs of robbery," Irvine Police Lt. Julia Engen told ABC News in an e-mail.

Police say they have very little to go on.

The couple met at Irvine's Concordia University where they both played on the school's basketball teams.

After college, Quan coached at Lutheran University in Thousand Oaks and has spent the past two years as an assistant coach at Cal State Fullerton. The university has posted a memorial page on their sports website dedicated to Quan.

"There are really no words to convey the sadness that our program feels, that the young women who have had the privilege of working with such a bright and passionate woman," said head coach Marcia Foster. "I want to especially send out condolences to Randal and Sylvia Quan, and her brother Ryan."

Monica Quan's father, Randal Quan, is a former captain in the Los Angeles Police Department.

Keith Lawrence was a business graduate who recently started working as a public-safety officer at USC.

"We are a better department and the USC campus community is a safer place as a result of his service," said Chief John Thomas.

Autopsies were performed on Quan and Lawrence today.

Police are requesting the public's help in solving the case and have setup a hotline which can be reached at 949-724-7192.