A mother noticed that a man at the Bethpage Air Show on Saturday was taking photos of her 5-year-old daughter, leading to his arrest on child pornography charges, police said.
John Meehan, 21, of North Babylon, was charged with possessing child pornography and unlawful surveillance, both felonies, state parks police said.
After the complaint at Jones Beach, investigators discovered that Meehan was possessing child pornography, police said.
In a subsequent search of his home, all his computer devices were seized for investigation.
The annual air show draws hundreds of thousands of people to Jones Beach State Park every Memorial Day weekend.