EVERGREEN, Colo. -- A music teacher at Evergreen High School and Evergreen Middle School has been placed on administrative leave following his arrest in a sexual assault investigation involving high school students.

The Jefferson County Sheriff's Office said that William Robert Eisenman, 32, is being held in the county jail on investigation of sexual assault on a child by one in a position of trust and sexual assault on a child, pattern of abuse.

Eisenman was arrested Wednesday after investigators looked into two separate allegations of sexual assault involving the teacher and female students at the high school.

Staff members at both schools were briefed on the investigation Wednesday.

"Clearly we're concerned about a teacher working within the school (having) that kind of contact with the students," said Jacki Kelley of the Jefferson County Sheriff's Office. "And we simply don't know how many more people this may affect."

The sheriff's office said that Eisenman had worked for Jeffco schools for the past school year and had previously worked for variety schools on the Western Slope.

Police said the assaults happened over a six-month period, but the court affidavits have been sealed and many key details remain private.

"Because this case involves juvenile victims and victims of sexual assault, the cases are so highly protected anyway," Kelley said. "We're being very, very cautious because we suspect there may be additional victims out there or witnesses that may be reluctant to come forward. So, the case is very protected."

Investigators said any additional victims and anyone with additional information is urged to contact the tip line at 303-271-5612.

Eisenman's next court appearance is scheduled for May 30.