GUILFORD COUNTY, N.C. (WGHP) — The process of vetting substitute teachers is being called into question after a sub was charged with inappropriate conduct.

Richard Martin, 73, is accused of having inappropriate relationships with students while employed with Guilford County Schools. A neighbor of Martin’s told FOX8 that something didn’t sit right with her about the man.

Martin’s legal record was only traffic violations until the charges were filed last week.

Officials with GCS say that substitutes go through the same background checks as part-time and full-time employees, completed by an outside vendor.

Martin was charged with statutory sex offense with a child, who was 13, and indecent liberties with a student. He’s also accused of contributing to the delinquency of a minor and felony drug possession.

Warrants state that there were two victims between the ages of 13 and 18. He was a substitute at Grimsley High School at some point during his time with GCS, which is where one of the victims was a student.

He’s accused of forcing a 13-year-old to take drugs and perform sexual acts.

An officer working on the case says that Martin has been committing sex crimes “for years” on children and expects additional charges to be filed.

He’d been working with GCS since 2017. As of April 26, he was no longer an active substitute.

“I feel bad for the parents and children that have to go through this, but I just hope Guilford County does better for our children,” Martin’s neighbor, who did not wish to be identified, said.

A child trauma specialist told FOX8 that parents should keep an eye out for odd behavior in their children, and asking about experiences at school or online could help identify a problem.

Martin is being held at the Guilford County jail on a $500,000 bond.

Anyone who thinks they have information about additional information is asked to report it.