Montgomery County Fire and Explosives arrested three teenagers in connection with the fire at Walt Whitman High School as well as a March 20 fire at White Flint Neighborhood Park.
Wyatt Randall Peter Dentel was charged with second-degree arson, first-degree burning and malicious destruction of property the park playground fire. He was charged with accessory to arson in the school fire.
Two 17-year-old Whitman students were with second-degree arson, first-degree burning and malicious destruction of property.
The fire at Whitman was set with a flammable liquid, authorities said, not an incendiary device, as originally reported.
