CHICAGO (CBS) — After a six-week investigation Riverside police arrested a Riverside Brookfield High School staff member suspected of transmitting harmful material.

On Dec. 30 a resident and her 17-year-old daughter filed a complaint with the department about the transmission of video showing nude male genitalia to the girl, who lives in Riverside. She is a student at Riverside Brookfield High School.

Anthony Roberts (Credit: Riverside Police)

During the investigation police got a search warrant for a Snapchat account that they say led them to suspect Anthony P. Roberts, who was working as a teacher’s aide and basketball coach at the high school.

Roberts was arrested Friday at the school. The school was not in session at the time, but it was a teachers’ institute day.

During the investigation police recovered numerous videos that were sent from Roberts to the girl. Photos of male genitalia were sent to her over an extended period of time.

There is no evidence that any physical contact took place between Roberts and any students or other children.

Roberts, who has no prior criminal history, is charged with one count of unlawful dissemination of harmful material, which is a misdemeanor.

Riverside Police Chief Thomas Weitzel stated, “Due to the sensitivity of this case, detectives worked directly with Snapchat in California to obtain records as soon as possible.  Our detectives received full cooperation from the Riverside Brookfield High School superintendent and his staff, and they continue to assist in the overall investigation.”

Anyone with further information or who believes they are also a victim should contact Riverside detectives immediately.