Prosecutors are seeking higher bail for a 69-year-old attorney charged with vehicular manslaughter and drunken driving in a Highway 12 crash that killed one bicyclist and seriously injured a second one near Oakmont two weeks ago.

Harvey David Hereford pleaded innocent in Superior Court on Monday, and will return Wednesday for a bail hearing. He is now free on $60,000 bail.

Deputy District Attorney William Brockley said Hereford's bail should be increased to $200,000 because "we feel he is a grave danger to the community." The level of alcohol in Hereford's system was more than three times the legal limit for driving, according to authorities.

Alan Liu, 31, of Mountain View, was killed when his bicycle was struck from behind on Highway 12 on April 11. His girlfriend, Jill Mason, 26, of Cupertino, who was riding ahead of Liu, suffered major head and back injuries. She is in serious condition at Santa Rosa Memorial Hospital, and Brockley said Monday that Mason has a severed spinal cord.

Liu and Mason, both multi-sport athletes, were training for triathlons at the time of the accident.

Hereford could be sentenced to nine years in prison if he's convicted of the charges, Brockley said.

Hereford's attorney, George Englar, said his client is a long-time resident of the Bay Area and is not a flight risk. Hereford lives in Oakmont and has a law office in San Francisco.

Judge Robert Dale said he'll consider the prosecution's request Wednesday after hearing a report from the Probation Department. He ordered Hereford not to drive or drink alcohol.

Hereford was placed in a county mental health facility after his arrest because he was deemed a danger to himself or others, according to authorities. He received treatment for chronic alcoholism and was later released.

Highway Patrol officers said Hereford was driving a 1995 Nissan Sentra westbound on Highway 12 near Pythian Road at about 11:20 a.m. on Easter morning when he swerved onto the shoulder and struck Liu. Then he hit Mason, who'd been riding about 100 feet ahead of Liu.

Hereford pulled over and was arrested by officers.

Witnesses said they saw Hereford driving erratically just before the crash.

Liu was a graduate of the Masschusetts Institute of Technology and worked as an engineer at Applied Materials in the Silicon Valley. He also was a swimming coach in Mountain View.

The couple were in Santa Rosa for Easter, visiting Liu's mother.

Mason recently earned a master's degree from San Jose State University. She works at a Silicon Valley engineering firm.