CALDWELL -- A former assistant coach at Kuna High could face a serious penalty - up to life in prison - if convicted in the wake of his Thursday arrest on drug charges.

Robby Lee Washington, 48, was fired from his position as the running backs coach for the Kuna Kavemen Friday morning.

Previous story: Kuna football coach fired after drug arrest

According to Nampa Police, an officer pulled Washington over in a traffic stop just after 2 p.m. After a drug dog alerted to the likely presence of drugs, the officer searched the car and found methamphetamine, cocaine, marijuana and a glass pipe, police say.

Washington, who was the only person inside the car, was arrested and booked into the Canyon County Jail. He faces felony drug possession charges for both the methamphetamine and cocaine, as well as misdemeanors for possession of marijuana and possession of paraphernalia with intent to use.

But it's a sentencing enhancement sought by prosecutors that could spell the most trouble for Washington: Prosecutors indicated they planned to argue that his prior criminal history qualifies him as a persistent offender.

If a judge agrees - and he is convicted of the drug charges - Washington's penalty could leap from a maximum of seven years for the felonies to maximum of life behind bars.

The prosecutor asked Judge Brian Lee to set bond at $100,000, pointing to Washington's criminal history and four previous instance in which he failed to show up to court.

The former coach pleaded guilty in 1994 to felony possession with intent to distribute and participated in a drug diversion program after another felony drug arrest in 2010, according to Idaho court records.

But Aaron Bazzoli, Washington's defense attorney, called a $100,000 bond "exceedingly high," noting that some of the earlier convictions prosecutors mentioned happened more than two decades ago. He asked the judge to release Washington on his own recognizance, or set a low bond.

Lee ultimately set bond at $10,000, ordering Washington to undergo pretrial monitoring and remain in Idaho if he posts bail. He's due back in court Oct. 13.

Washington's arrest has also spurred investigations in the Kuna School District.

District spokesman Dave Reinhart said Washington was added to the coaching staff last year, during a "period of transition" within the human resources department. Although a background check was performed, it's not clear whether Washington's criminal record and status as a felon was communicated before he was hired, he said.

"It's not clear who knew what. Processes weren't followed," Reinhart said. "Our job now is to review those procedures so there are no gaps."

In addition to shoring up hiring procedures, the district is also reviewing the files of every employee - including Reinhart - hired between July and November 2015, while the HR department was in flux.

The arrest appears to have no link to Washington's position at Kuna High, Reinhart said. School officials will make counselors available to students next week.