The investigation into Stephen McDonough, a gym teacher in Belmont and Waltham, was initiated in late August after the Massachusetts State Police Cyber Crime Unit received a tip from the National Center for Missing and Exploited Children about suspicious online activity linked to his Waltham residence.

Law enforcement executed a search warrant at McDonough's home on September 25, 2025, uncovering digital evidence on his phone and property that indicated ownership and sharing of child pornography, stemming from the ongoing investigation.

McDonough was charged with possession and dissemination of child pornography and was arraigned in Waltham District Court, where he was held on a $25,000 cash bail with restrictions including no unsupervised contact or employment involving minors under 18.

His role as a school gym teacher raised concerns due to his access to children, prompting authorities to notify the Belmont and Waltham School Districts about the allegations.

Multiple law enforcement agencies, including state police, local police, and Homeland Security, participated in the arrest and investigation.

Police have alerted the school communities and urged the public to report any related information to 911 to assist ongoing child exploitation cases.

McDonough is scheduled to return to court on October 22, 2025, and is currently held on a $25,000 bail, with authorities emphasizing the importance of community cooperation.

Authorities continue to investigate and are asking the public for additional information to help with the case.

The charges against McDonough are based on probable cause that he owned and shared illegal materials, with the investigation revealing evidence linking him to the possession and distribution of child abuse images.

Community safety remains a priority, and law enforcement urges the public to report any information related to child exploitation.