A Canonsburg man who worked as a substitute teacher in Mt. Lebanon, pleaded not guilty Wednesday to multiple charges, including institutional sexual assault during a preliminary hearing before Mt. Lebanon District Judge Hilary Wheatley. Twenty-four-year-old Damon Gall was a substitute teacher at Seton LaSalle Catholic High School at the time of the incident in December 2023. In addition to a charge of institutional sexual assault, Gall is facing charges of corruption of minors and indecent assault. Gall will be formally arraigned in April in Allegheny County Common Pleas Court. A criminal complaint filed against Gall said that he confessed to Mt. Lebanon police. Gall previously worked in the Ringgold School District in Washington County. (Photo: Allegheny County)