INDIO, Calif. -

A murder charge was filed Monday against a woman accused of driving under the influence and causing a fiery head-on collision that killed a 65-year-old woman in Desert Hot Springs.

Monica Hernandez Benavidez, 34, pleaded not guilty. She was ordered held on $1 million, and Riverside Superior Court Judge William Lebov granted a request from her attorney to have his client examined by the jail's medical staff.

It was unclear what medical problem Benavidez might be suffering from.

Aside from the murder charge, she is also charged with two felony counts of DUI causing injury and a misdemeanor count of driving with a suspended license in the June 5 crash that killed Desert Hot Springs resident Maria Soto Caballero and seriously injured two other people.

Benavidez was driving south on Palm Drive near Camino Campanero when she allegedly swerved into northbound lanes and collided with another vehicle, according to police.

Caballero died at the scene, and the two other people in the vehicle were seriously injured.

Police said Benavidez was driving under the influence of alcohol and drugs.

Under California's so-called Watson murder rule, named after a precedent-setting 1981 state Supreme Court case, a person driving under the influence in a fatal crash can be charged with second-degree murder if they have a previous DUI conviction.

According to court records, Benavidez pleaded guilty in 2012 and 2006 to misdemeanor driving under the influence counts, pleaded guilty in 2008 to driving with a suspended license and was charged last year with DUI and driving with a suspended license.

She was arrested after being released from a hospital Thursday and booked into the Robert Presley Detention Center in Riverside in lieu of $1 million bail.

She is due back in court July 2 for a felony settlement conference.