Gambrell (AP) - A defense attorney for a bus driver charged in a November crash that killed four people said Tuesday she will challenge an accusation that the man was under the influence of amphetamines at the time.

    Lawyer Tonya Alexander of West Memphis told The Associated Press she will call in scientific experts to challenge tests done by the state Crime Laboratory on pills carried by Felix Badillo Tapia, 28, of Brownsville, Texas. He faces four counts of negligent homicide stemming from the Nov. 25 bus crash.

    "I think we'll beat science with science," Alexander said.

    Alexander, who missed a previous court appearance on Tapia's behalf, appeared Tuesday before St. Francis Circuit Court Judge Harvey Yates.

    Yates set an Aug. 25 trial date for Tapia, who was driving the Tornado Bus Co. bus when it crossed the median on Interstate 40 near Forrest City. The bus slammed into a pickup truck and a tractor trailer, killing three bus passengers and the pickup's driver. More than 20 others were injured.

    According to a state police affidavit, Tapia had a small metal pill holder on him that contained a green capsule he initially identified as headache medicine. Troopers reported also finding a blister pack of the same drugs tucked into a falsified log book. Later, Tapia described the capsule as a diet pill he purchased in Mexico.

    The state Crime Laboratory identified the drug as Itravil, a compound made in Mexico and banned for sale in the United States. The drug works as an amphetamine.

    Alexander said the drug was a diet pill, challenging the idea that Tapia used the drug as a stimulant to stay awake while driving the Tornado bus from Chicago to Dallas. A state police investigation found Tapia drove the route alone, without a relief driver as required by law.

    "He was not intoxicated," Alexander said. "They found diet pills, they didn't find amphetamines."

    Alexander declined to comment further on the case.

    Prosecutor Fletcher Long previously said he was frustrated with the case's slow progress to trial, saying Tapia could be a flight risk. Tuesday though, Tapia sat in the court room with another man. Tapia, dressed in a blue dress shirt, kept his head down as he waited, occasionally wiping at his eyes.

    Tapia remains free on $50,000 bond pending trial. If convicted, Tapia could be sentenced to up to 10 years in prison and a $10,000 fine on each count.