Wayne Richard, 33, was caught by undercover officers at a Shop Rite in Wilmington.
A police canine searched the interior of his car and found a Diet Coke can with 10 grams of cocaine inside that had been packaged for sale.
Police later searched Richard's home and found additional cocaine, drug paraphernalia and a handgun.
During the course of their investigation, police discovered Richard is a school teacher and behavioral interventionist at the Harlen Elementary school in Wilmington.
Richard has been charged with trafficking cocaine, maintaining a dwelling for keeping a controlled substance, maintaining a vehicle for keeping a controlled substance, two counts of possession with the intent to deliver cocaine, possession of a firearm during the commission of a felony, and possession of drug paraphernalia.
Richard was arraigned and released after posting bail.