Voskanian was arrested last month after a three-month investigation into the Sept. 15 death of 80-year-old Misak Ranjbar, who was in a crosswalk at California Avenue her car hit him.
After being thrown into the air, Ranjbar landed on the pavement, and Voskanian stopped shortly after the collision to remain at the scene, police said.
He was taken to Los Angeles County-USC Medical Center, where he died of head trauma, coroner's officials said.
Glendale police officials said Voskanian was texting when she drove through the stop sign at the intersection.
But her attorney said the police report for the crash was littered with hypotheses, and he rejected the allegation that Voskanian was texting at the time of the collision.
"I have 37 years' experience, and I have never seen a police report full of suppositions and conjectures without any concrete evidence," Levinson said, adding that he thought his client was being used as a "political vendetta."
The Los Angeles County district attorney's office has maintained that Voskanian had been driving while "in the commission of an unlawful act."
District attorney's office officials said they filed charges against Voskanian based on a careful review of the evidence, which a spokeswoman said would be revealed at the preliminary hearing.
Levinson said he will enlist the help of accident reconstruction specialists and a private investigator to bolster his case.
"We are going to try to win this in preliminary hearing and not go any farther," he said.