In court, Veen said Le Moullac was wearing a helmet but her head was crushed and she was left bleeding in a crosswalk at the intersection of Folsom and Sixth streets.

A Muni driver passing the scene around 7 a.m. brought a bus full of passengers to a stop and rushed to Le Moullac's side. The driver, Anna Contreras, a former Army medic, fought tears on the witness stand as she described how she found Le Moullac unconscious and breathing shallowly.

Le Moullac was transported to San Francisco General Hospital, where she was pronounced dead at 8:20 a.m.

Driver's Conflicting Stories

Veen said Le Moullac was alert and "doing everything within the law" when she was riding her bike, heading to the Caltrain station at Fourth and King streets. He accused Alcantar of giving conflicting stories, and said he failed to change lanes safely -- as the law requires -- and, based on a witness account -- did not have a turn signal on.

Veen said Alcantar saw Le Moullac pedaling eastbound and passed her on Folsom Street, but later lost sight of her -- and without slowing down, turned right across the bike lane, southbound onto Sixth Street.

"She didn't have a chance. It was unavoidable for her but very avoidable for Mr. Alcantar," said Veen.

Rather than dial 911, Veen said Alcantar stopped the truck and called his employer after running over Le Moullac while other people came to her side.

In his opening statements, Alcantar's attorney, Brent Anderson, alleged Le Moullac was wearing earbuds and was distracted. A photo displayed in court showed a piece of Le Moullac's helmet found at the scene tangled in what Alcantar's attorney said were earbuds.

That allegation was disputed by Contreras, the Muni driver, who testified the helmet was "intact" and Le Moullac did not have any buds in her ears.

Anderson claimed the truck slowed to 7 mph before turning onto Sixth Street, and that Alcantar did use his signal. He alleged Le Moullac was riding "two times as fast" and "caught the truck and was passing it on the right while the truck was making a right."

"Those were the choices that she made," Anderson told jurors. "We think it is unfair to blame Mr. Alcantar for this accident."

Anderson said bicyclists have an "obligation" to pass on the left of a right-turning vehicle, which is good safety advice but not actually the law, according to the California Vehicle Code.

That same passing advice was told to bike advocates by an SFPD sergeant who blocked the bike lane at a memorial for Le Moullac. The sergeant, who was later disciplined, had blamed Le Moullac and other cyclists who have been killed for their deaths.

The law says that bicyclists have the right-of-way in a bike lane, and right-turning drivers are supposed to safely merge into the bike lane where the solid line becomes dashed, and yield to bicyclists.

Le Moullac's family filled one side of the small courtroom. Her mother and father wept at times. Veen described their daughter "as the glue that held the family together." Alcantar, dressed in a black suit, sat on the opposite side.

The trial in San Francisco Superior Court is expected to last a few weeks.