A man has been arrested for allegedly capturing video of a boy in the locker room at Chelmsford High School, authorities said.

The boy was changing and in a state of nudity when he observed a man about 15 feet away in the locker room holding a cell phone. The man appeared to be video recording him, leading the boy to alert several coaches, Chelmsford Chief of Police James Spinney said in a press conference Saturday night.

There were 21 different school districts present at Chelmsford High School for a wrestling event.

A group of coaches then detained the suspect, Waltham resident David Menard, 54, and brought him outside the school building. Police arrived at the school a couple minutes later, around 4:15 p.m.

Police said that Menard had willingly handed his phone to the coaches who confronted him. Officers later found multiple cameras, laptops and recording devices inside his car, and are waiting on search warrants to study the devices for further potential evidence.

"That leads one to believe that it is a concern as to regular activity by this individual, so we could be talking about multiple jursidictions, and multiple victims," Spinney said.

The high school was hosting the Chelmsford Invitational Tournament Saturday with 21 school districts competing at the time, according to Spinney.

Menard did not seem to be connected to the wrestling event beyond spectating, police said.

Spinney did say that the man seems to have been captured on surveillance camera in the hallway entrance to the locker room.

He has been charged on allegations of possessing child pornography and videotaping a nude person, and may face more as the investigation progresses, according to Chelmsford police.

"I have not come across this in Chelmsford — I have been a police officer here for 30 years and this the first time I am aware of an event like this in this community," Spinney said. "It is a reminder that we are a part of a connecting world and this could happen anywhere."

Menard will be arraigned in Lowell District Court on Monday.