Sarah Jean Cowman, 29, faces a felony charge of delivering heroin and is expected to be placed on paid leave pending the outcome of the investigation, police and school district officials said.
Cowman posted $5,000 bond Friday and is scheduled for a preliminary hearing Feb. 10 on the charge of delivering a controlled substance, according to court records.
Cowman is a second-grade teacher at Hawthorne Elementary School but has been replaced in the classroom by a "qualified long-term substitute teacher," Boise School District spokesman Dan Hollar said Friday.
"She is not in the classroom," Hollar said. "She has not been in the classroom since her arrest. This does not involve any activity in the classroom or at the school or involving any students."
Boise police said Cowman had been under investigation since late December by the Boise Area Narcotics and Drug Interdiction Team. Once probable cause was established, officers arrested Cowman Wednesday at a convenience store near the intersection of North Mitchell Street and West Fairview Avenue, police said. She was booked into the Ada County Jail early Thursday morning.