Why guns are good? Also does anyone know the name of a woman involed in a shooting who was part of the NRA?

Okay. I have to argue why guns are good in a debate and mention "Bowling for columbine". Does anyone know any points I can say. Also more importantly there is this lady and i need to know her name. There was a shooting in America (i think in a burger joint) and a lady who was a marksman argued that if she had her gun on her she could have stopped the shooter. Does anyone know her name?