SAN DIEGO -- A painkiller that a toxicologist allegedly used to kill her husband was missing from the San Diego County Medical Examiner's Office where she worked, employees testified Wednesday.

Kristin Rossum, 24, is accused of poisoning her husband and covering his head and chest with rose petals in a scene that police said resembled her favorite movie, "American Beauty."

Prosecutors say Rossum gave her husband, Gregory DeVillers, 26, an overdose of the powerful painkiller fentanyl in November 2000.

She is charged with murder with special circumstances and could get the death penalty if convicted.

An audit that month found that 10 milligrams of fentanyl and 15 patches of the drug that had been logged into the medical examiner's office in 1997 were missing, Donald Lowe, a toxicologist with the office, said.

At a preliminary hearing, Lowe testified that he called police two days after DeVillers' death and told them Rossum and her boss, Michael Robertson, had been having an affair.

"They looked like they were closer to each other physically than would be appropriate," he said.

Lowe also testified that Rossum was fired in December from the medical examiner's office for drug use, but he did not name the drugs.

Testimony was scheduled to continue Thursday in San Diego County Superior Court.