Unknown song - everybody look and see everybody run, everybody look and see Johnny's got a gun

I am trying to find this song from the 60's/70's.

I am fairly sure it was sung by a female.

It was around at the same time as Chris Andrew's song Pretty Belinda.

The lyrics I can recall from many years back are as follows...

Little Johnny's (or Tommy's) had reached down in to his *something* pocket, *something something something something* he began to shoot it.

*something something and something something fall between his fingers, women and children hide behind his trigger, everybody look and see everybody run, everybody look and see Johnny's (or Tommy's) got a gun.

The songs last line slows down as it goes through these words... something something and darkness and the something has just begun

I would call it a pop song of the era.

I know it's not much to go on, but I would truly love to find the song and enjoy it all over again