MAHANOY CITY (AP) — An 18-year-old Mahanoy Area senior charged with writing a bomb threat on a school bathroom wall earlier this year waived his right to a preliminary hearing Thursday after prosecutors withdrew the most serious charge against him.

Joseph R. Flaim was scheduled to appear before Magisterial District Judge Anthony J. Kilker, Shenandoah, on charges of one felony count each of threat to use weapons of mass destruction and terroristic threats along with one misdemeanor count each of criminal mischief and disorderly conduct.

After prosecutors withdrew the charge of threat to use weapons of mass destruction and reduced the terroristic threat charge from a felony to a misdemeanor, Flaim decided to have the current charges against him heard in Schuylkill County Court.

In paperwork filed with the court, Mahanoy City police Patrolman Christopher Zubris said that between 9 and 9:30 a.m. Oct. 18, school resource officer Jonathan McHugh was contacted by a school official who said a bomb threat was written on a wall in one of the boys’ bathrooms.

Zubris said the discovery prompted the evacuation of all students, faculty members and support staff.

At the scene minutes later, Zubris said, he and McHugh conducted a search of the school complex to ensure everyone was evacuated and then contacted the Schuylkill County Emergency Management Agency and the state police bomb detection K-9 unit for assistance.

A state police K-9 unit specially trained in bomb detection arrived, searched the school and school grounds, and determined no explosive device existed.

The investigation led to the review of surveillance video that showed between 7:06 and 9:18 a.m., 20 male students entered and exited the bathroom, Zubris said.

The following day, Zubris said, school officials began interviewing the 20 students and two admitted using the third stall where the threat was written.

Officials then requested and received writing samples from all 20.

Zubris said he interviewed Flaim, one of the two students who admitted using the third stall, in the presence of his parents and school officials. At that time, the officer said Flaim denied writing the threat, but he said he did not have access to a pencil to even write the threat.

At that point, Zubris said, it was never disclosed that the threat was written in pencil.

Zubris said Flaim then left the school and sent his father a text message saying he would like to speak with the officer alone to discuss the matter.

On Oct. 22, Zubris said, Flaim came to the police station where he was read his Miranda Rights, but he again denied involvement in the threat despite being confronted with the evidence against him.

Then, on Oct. 23, Zubris received a message from Mahanoy Area School District Superintendent Joie Green, who said Flaim was in her office confessing to writing the threat.

At the school, Zubris again reminded Flaim of his rights and during a conversation Flaim admitted writing the threat and said he lied the day before because he did not want the officer to be disappointed in him.

Flaim was formally arraigned Nov. 8 and remains free on $25,000 unsecured bail set by Kilker at that time.