SAN DIEGO -- A former county toxicologist who allegedly poisoned her husband with drugs stolen from her office pleaded innocent Monday to charges of murder.

Kristin Rossum, 24, appeared in San Diego County Superior Court with a reddened face and broke down in tears when her father spoke on her behalf to request bail.

Ralph Rossum noted that his daughter has cooperated with authorities throughout the eight-month investigation into the death of Greg de Villers.

"Mexico is very close. She could have left at any time," he said.

"She would not jeopardize our love and our financial future."

Judge David Szumowski denied bail, citing the seriousness of the charges. Rossum is accused of murder and the special circumstance of murder by poisoning, which could have her face the death penalty.

Prosecutors say Rossum killed her husband by giving him an overdose of the powerful painkiller fentanyl, which she allegedly took from her job at the San Diego County Medical Examiner's office.

De Villers, 27, was found dead at their apartment in the married-student housing section of the University of California, San Diego, on Nov. 6. He was discovered in their bed, rose petals scattered around his body.

Rossum told investigators her husband killed himself. Prosecutors say Rossum tried to make the death look like a suicide and note that at the time she was having an affair with her supervisor at the medical examiner's office.

Rossum and the supervisor, Michael D. Robertson, were fired from the office in December. He has since returned to his native Australia.

Prior to Monday's hearing, Rossum requested that a public defender be appointed to her case. Rossum's father, a professor at Claremont McKenna College and a former Justice Department official in the Reagan administration, said the family could not afford to keep the private attorneys they initially hired.

Szumowski scheduled a preliminary hearing for July 16, but noted the date likely would be changed to give the defense more time to prepare.