San Juan investigators told Action 4 News that Edgar Olivo and another teen set fire to the Dollar General located on Raul Longoria, early Tuesday morning.
Olivo and the teen admitted to police that they used cardboard boxes to fuel the flames.
Crystal Maldonado was also arrested---accused of helping the duo burglarize a vehicle.
Both Olivo and the juvenile admitted to being members of Sureno 13.
Sgt. Rolando Garcia told Action 4 News they see an increase in crime during the summer months"dealing with juveniles.
"They'll use these kids and have them do their dirty work. It's not so much a loss to them. They will do it for 100 to 150 bucks and for a child that is a lot of money."
Olivo and the juvenile were charged with arson and burglary of a vehicle. Maldonado was charged with burglary of a vehicle.