Robert Alan Lehmann

Robert Alan Lehmann (Courtesy Costa Mesa Police Department / September 18, 2012)

Opening statements in the trial of a Costa Mesa man accused of killing his ex-wife and her father over a child custody dispute are set to begin Wednesday in Santa Ana.

Robert Alan Lehmann, 37, faces two felony counts of murder and two felony counts of using a firearm, with sentencing enhancements for lying in wait and committing multiple murders.

Lehmann is suspected of killing Emily Ford, 32, and her father, Russell Ford, 62, when they went to Lehmann's home on Santa Clara Circle to take custody of their daughter, who was 7 at the time, according to court records and the Orange County district attorney's office.

Prosecutors said that on May 3, 2011, Lehmann sent the special-needs girl and his wife to buy ice cream while he waited for Emily Ford to arrive to take custody of the girl.

When the Fords arrived, Lehmann opened fire on the two, with bullets passing the car where Emily Ford's 3-month-old son waited, prosecutors said.

As the two tried to run away, Lehmann allegedly chased them. At one point, he reloaded his gun during the attack, prosecutors said.

Emily Ford worked as a special-education preschool instructional aide at Paularino Elementary School in Costa Mesa and waited tables part time at Morton's steakhouse in the South Coast Metro area of Santa Ana.

Russell Ford was a 32-year veteran educator at the Santa Ana Unified School District.

Lehmann's neighbors said at the time that they were shocked at the violence. They said Lehmann always seemed very affectionate toward his daughter and would often play with her outside.

lauren.williams@latimes.com

Twitter: @lawilliams30