Fountain Valley detectives are asking the public's assistance in finding the white Volkswagen van driven by the suspect in Tuesday's murder of a doughnut shop manager during a robbery. Detective Darryl Nance said the van is a mid-to-late 1960s model with a distinctive red Department of Motor Vehicles sticker bearing the number "2" in the back window. The first two digits of the seven-digit plate are 2A and the last three are 784, Nance said. An autopsy revealed the victim, Virgie Ella LaFountain, 57, of Fountain Valley, died of a single gunshot wound to the chest. Nance said a small-caliber handgun was used, and $59 was taken from the register at Yum Yum Donuts, 17217 Brookhurst St., Fountain Valley. There was no sign of a struggle, Nance said.