ASTON TWP., Pa. — A middle school counselor in Delaware County, Pennsylvania, has been charged with possession of child pornography.

Kevin Siegel has been a counselor at Northley Middle School in Aston Township for more than two decades.

The district says he was immediately relieved of his duties after being charged.

The investigation into this illegal activity began on September 13.

Siegel was first reported by Yahoo to the National Center for Missing and Exploited Children for inappropriate online activity.

In a video posted on the district’s YouTube page in February, longtime Penn-Delco advisor Kevin Siegel is seen offering advice to students.

He has now been arrested and charged with 17 counts of child pornography.

“It was stupid, it was a moment of weakness,” the 46-year-old man allegedly told police when confronted by investigators, adding that he “wasn’t thinking straight.”

But after a search warrant, more than a dozen sexually explicit images of teenage girls ages 7 to 11 were found on his multiple devices, according to the criminal complaint.

Investigators say Siegel emailed the images to himself. They also say Siegel used special programs to find and download specific child abuse material.

The Delaware Division of Criminal Investigation began investigating Siegel following a tip from Yahoo.

Siegel is an eighth-grade counselor at Northley Middle School and has held that position for 22 years. He is also listed as the school’s cross country and track and field coach.

Over the weekend, the Penn-Delco School District sent a letter to parents that read in part: “Mr. Siegel was immediately removed from his workplace, placed on leave, and had no contact with students from the time the district was first notified.”

They continue: “Law enforcement representatives reiterated that none of the crimes allegedly committed by Mr. Siegel occurred on school property or involved current or former Penn-Delco students.”

Bail was set at $100,000. His next hearing will be held on December 5.