An elementary school substitute teacher for Prince George’s County Public Schools has been arrested on charges of possessing and distributing child pornography, according to police.

Investigators executed a search warrant Thursday at the Capitol Heights home of Christopher H. Speights, 34, and seized several electronic devices containing material of young children performing sexually explicit acts, according to Maryland State Police.

Detectives interviewed Speights after the search of his home, and police charging documents say he admitted to uploading images of child pornography to a Dropbox account with his cellphone, tablet and computer.

Detectives found 153 files containing graphic photos and images, mostly of young boys about 10 to 12 years old, according to the charging document.

Greg Shipley, a spokesman for Maryland State Police, said it is too early to tell whether any of the images of children depict students with whom Speights interacted through coaching or teaching.

Speights has taught and coached at Bradbury Heights Elementary School in the Capitol Heights area, court files state. Police said Speights also is or has been a South County Sports Academy basketball coach.

“We know he had child pornography on his devices and he also was in a job or jobs where he had associations with children,” Shipley said. “To connect the two yet, we can’t say.”

In a statement, Prince George’s County Public Schools said that the school system is aware of Speights’s arrest and that he no longer will work for the district.

Speights has worked for the school system for about nine years, according to court documents.

Maryland State Police began looking into the case in December after the National Center for Missing & Exploited Children submitted a tip from Dropbox flagging the possible possession and distribution of illegal content, charging documents state.

Speights’s arrest comes about three months after a former Prince George’s County elementary school teacher’s aide and volunteer, Deonte Carraway, pleaded guilty in federal court to child pornography charges involving more than a dozen students.

The school system said in a statement after Speights’s arrest that “any behavior that brings harm to a child will not be tolerated in any way in PGCPS.” Over the past year, it continued, “we have made significant changes to increase student safety and remain committed to ensuring a quality education in a safe environment for all students.”

Police are asking parents whose children may have been affected by the Speights case to contact investigators at 410-953-8272.