Grieving relatives of a couple killed in a crash on Route 202 grimaced as a 20-year-old Chester County man today entered a not-guilty plea to charges that include homicide by vehicle, driving under the influence of drugs, and fleeing an accident.

Brian J. O'Neill, appearing in Exton district court, waived his preliminary hearing on offenses stemming from an early morning crash on Sept. 6 that killed Diane Washington, 45, and her husband of 11 months, George Parker, 47 - both of Norristown.

West Whiteland Township police said O'Neill, who was found running from the accident scene, had been driving the wrong way on Route 202 when his 2006 Dodge Dakota collided with the victims' 1995 Suzuki Sidekick. After being detained by an officer, O'Neill jumped a guardrail, falling 36 feet, the criminal complaint said.

He was flown to the Hospital of the University of Pennsylvania, where he was treated for non-life-threatening injuries, according to the complaint. Toxicology tests indicated O'Neill had marijuana in his system to a degree that rendered him "unfit to safely operate a motor vehicle," the complaint said.

Diane Washington's sisters, Donna and Denise, said the holidays have made the family's loss even more painful.

"I just want him to be accountable," Rose Young, Parker's grandmother, said of O'Neill.

Donna Washington expressed concern that O'Neill, son of Thomas J. O'Neill, a West Chester lawyer, had received and would continue to receive preferential treatment. He has been free on 10 percent of $50,000 bail since his arrest last month.

"I would have been arrested that night if I were responsible for killing two people," Donna Washington said.

Chief Deputy District Attorney Robert L. Miller and Brian O'Neill's attorney, Daniel Bush, both said no favoritism occurred.

"I know this D.A.'s office, and they don't work that way," Bush said, calling the case "an awful tragedy for all three families."

Contact staff writer Kathleen Brady Shea at 610-696-3815 or kbrady@phillynews.com.