latoya tilson , 33 , took out a .25-caliber handgun and fired several times into the feuding crowd in college park , georgia , on saturday night after she was hit in the face by someone , police said .
but while one bullet struck a 17-year-old boy in the buttocks , another hit tilson 's 15-year-old son , pierre , in the head .
pierre was rushed to grady memorial hospital with a gunshot wound to the back of his head .