LOS ANGELES - A woman accused of felony gross vehicular manslaughter after allegedly plowing into a crowd of people leaving a Christmas concert Wednesday night, killing four people, including a 6-year-old boy, has pleaded not guilty.

Margo Bronstein, 56, of Redondo Beach, was wheeled into a Torrance courtroom on a stretcher and arraigned Friday on four felony counts of gross vehicular manslaughter while intoxicated and one felony count of being under the influence of a drug, causing injuries.

She's due back in court Jan. 14 and is being held on $500,000 bail - a sum her attorney unsuccessfully opposed.

"This is one event, and it seems like bail is being stacked," said Jeffrey Gray, Bronstein's attorney.

After the hearing, Gray addressed reporters outside the Torrance courthouse and said it seemed everyone was jumping to conclusions about Bronstein and the crash.

"My concern is that there seems to be almost a mob mentality with this case," he said. "We should not engage in speculation - it's not fair to any of the parties involved."

He said there were many facets that needed to be explored with the case, including the possibility of mechanical failures in Bronstein's car or an adverse reaction to her prescription medications. He would not elaborate on either point.

"Obviously she feels terrible," he said. "This is an accident."

Authorities said Bronstein was behind the wheel of the car that ran through a crowd outside St. James Catholic Church in Redondo Beach. Prosecutors allege she swerved around vehicles stopped at a red light before striking the crowd.

If convicted of the charges, she could face 40 years in prison.

Bronstein, who friends said relied on a motorized wheelchair, had a clean driving history. She was restricted to driving a car with hand-controlled brakes, authorities said.