The Pittsburgh synagogue shooting was an antisemitic terrorist attack that took place at the Tree of Life Synagogue in Pittsburgh Pennsylvania. On Oct. 27, 2018, an active shooter entered the Tree of Life Synagogue in Pittsburgh, where members of the Tree of Life, Dor Hadash, and New Light Jewish congregations gathered to engage in religious worship. The assailant entered the building armed with multiple firearms, including three Glock .357 SIG pistols and a Colt AR-15 rifle. While inside the Tree of Life Synagogue, the assailant opened fire, killing and injuring members of the three congregations. The horrific attack at the Tree of Life Synagogue on October 27, 2018, stole the lives of 11 innocent victims, wounded six others, including first responders as they attempted to rescue surviving victims. It was the deadliest attack on any Jewish community in the United States.

Steve Mescan is a 30-year veteran of the City of Pittsburgh Bureau of Police and has been a member of the SWAT Team for 25 years. He recently retired from his position with the SWAT Team's Tactical Operations Section, which is comprised of subject matter experts who assist the City of Pittsburgh Bureau of Police command staff personnel with strategic initiatives, planning, and tactical resolve contingencies as they relate to all police operations. During his tenure with the Pittsburgh SWAT Team, he performed various roles, from entry operator to sniper, team leader, trainer, and tactical commander. He has been an instructor for the NTOA for over 18 years and co-authored the NTOA Team Leader Development Program. He has instructed numerous state tactical associations and has consulted as an expert to area SWAT Teams concerning SWAT operations. In 2009, he was part of a subject matter expert team that developed the tactical strategic plan for the G-20 Summit held in Pittsburgh, Pennsylvania. In 2018, he was the SWAT Team Leader involved in the response to the Tree of Life Synagogue Massacre. As of January 2024, he accepted a full-time position with the National Tactical Officers Association as the Director of Training and Education. Steve is the past president of the Pennsylvania Tactical Officers Association (PATOA), he served as the NTOA Eastern Director for 10 years and during his last two years as the Chairman of the Board of Directors for the NTOA.

Andrew Miller began his law enforcement career with the Pittsburgh Police in 2009 and remains employed there. He has worked in several capacities, including Patrol, Zone Plainclothes, Major Crimes Detective, Narcotics Detective, and most currently with the Fugitive Apprehension Unit. He has been a SWAT operator since 2013 and a Team Leader since 2016. He has participated in numerous search warrants and arrest warrants., barricades, hostage rescues, and active shooters. He has been an adjunct instructor for less lethal munitions and taught several basic and advanced SWAT courses for the Pittsburgh Bureau of Police SWAT course.