VISTA (CNS) - A motorist accused of hitting a bicyclist in Carlsbad and fleeing the scene of the fatal crash pleaded not guilty Thursday to gross vehicular manslaughter, hit-and-run and drunken driving charges.

Julianne Elyse Thomson, 23, was ordered held on $200,000 bail in the July 27 death of 64-year-old Arthur John Jacobs of Vista.

Thomson had been out of custody on $100,000 bail, but Judge Marshall Hockett doubled the amount -- saying the defendant was a danger -- and she was taken back to jail.

The defendant faces 15 years in state prison if convicted of the three felony charges, said Deputy District Attorney Aimee McLeod.

Jacobs was fatally struck while riding his bicycle near the intersection of El Camino Real and Cassia Street around 9:45 p.m. on July 27.

A witness told police the driver crashed into a curb and some bushes, then sped away into an apartment complex parking lot, Carlsbad police Lt. Paul Mendes said. Arriving emergency personnel pronounced Jacobs dead at the scene.

McLeod said Thomson was found about 15 minutes later on the opposite side of the apartment complex, where she had parked her car.

The defendant's blood-alcohol level was measured at .25 percent, more than three times the legal limit for driving, the prosecutor said.

Hockett set a readiness conference for Aug. 12 and a preliminary hearing for Aug. 17.