A Concord elementary teacher has been arrested on suspicion of child sex crimes, officials said.
Joseph Andrew Martin, a fourth- and fifth-grade teacher at Woodside Elementary School, was arrested Thursday at his home in Martinez.
Martin, 45, is being held at the Contra Costa County Jail on multiple counts of committing a lewd act on a child, police said. Bail is set at $3.95 million.
Authorities began an investigation on April 25, when police responded to the elementary school after a campus administrator reported a teacher inappropriately touched a student.
The school district placed the teacher on administrative leave while officers conducted a preliminary investigation. The case was then handed to the Concord Police Department's Special Victims Unit, who conducted an extensive investigation over the course of the next eight weeks, police said.
Several witness interviews were conducted, including 12 juvenile victims who were current or former students of Martin, police said. The victims' ages ranged from 11 to 17 years old.
Police said most of the acts are believed to have taken place on campus.
Martin has been employed by the Mt. Diablo Unified School District since 1991.
Detectives said they will hand the investigation to the Contra Costa District Attorney's Office on Tuesday. The DA will then review the investigation and determine if criminal charges will be filed against Martin.
Officials are not releasing any additional information at this time.
Police encourage anyone who has been treated in an inappropriate manner by Martin to contact the Concord Police Department Special Victims Unit at 925-603-5836.