SAN DIEGO -- A man accused of stealing a car from a woman and her mother at gunpoint in Chula Vista and trying to run over two CHP officers during a subsequent chase that ended in San Bernardino is mentally incompetent to stand trial and will be sent to a state mental hospital, a judge ruled Friday.

Fred Eugene Hiser, 42, will remain at Patton State Hospital pending the results of further examinations to determine mental competency.

At a hearing today, Judge Frederick Maguire ruled that Hiser did not understand the charges against him and couldn't assist in his defense.

The defendant is charged with two counts each of assault with a semiautomatic firearm and assault on a peace officer, and one count each of carjacking with a gun, robbery with a gun, elder abuse with a gun, auto theft and recklessly evading police -- all felonies -- along with a misdemeanor count of resisting arrest.

The defendant faces 29 years in prison if convicted.

Hiser, of Chula Vista, was arrested the night of July 5 after officers ended a pursuit by putting down a spike strip near the Cajon Pass in San Bernardino.

At the defendant's arraignment, prosecutor Michael MacNeil alleged that Hiser approached a woman and her 75-year-old mother at gunpoint just before 6 p.m. as they walked along the bayfront and demanded the younger victim's keys.

MacNeil said the victims got into the car of a good Samaritan and followed their assailant until police could take up the chase.

During multiple attempts to throw out spike strips to stop the vehicle, one CHP officer broke a finger and another had to run and dive for cover over a center divider, MacNeil said.