DeKalb County police are searching for a man who brought a loaded gun to a high school campus just days before the start of school year.

 School officials say alert behavior by the principal may have prevented a more dangerous situation during an open house event at Towers High School in Decatur.

 Principal Donevin Hoskins noticed a man acting suspiciously on Wednesday evening and asked him to leave the building, officials said.

 Hoskins told police he saw the man drop a skull cap on the ground, and inside the cap was a loaded 9 millimeter pistol.

 Hoskins got into a skirmish with the man as they both reached for the gun, and the man eventually ran off, according to a police report obtained by Channel 2’s Amy Napier Viteri.

 Yvette Heath heard about the incident while enrolling her family at the school on Thursday.

 “It was heroic on his part,” Heath told Napier Viteri. “It was at an open house, so who would expect that?”

 Investigators say cameras inside the school showed the man walking the hallways after the open house, but they have not yet identified him.

 Classes for all DeKalb County public school students begin on Monday.