Lyrics: "Everybody look and see everybody run, everybody look and see Johnny's (or Tommy's) got a gun"
More partial lyrics from my memories: Little Johnny's (or Tommy's) hand slipped down into his something pocket something something something something he began to shoot it.
Link to youtube of me singing a part of the chorus as I remember it.
I used to listen to it on vinyl, but I can't remember if it was a mixed artist record or not.
I'm fairly certain it was a female singing.
I think the song was from the 60's/70's, around at the same time as Chris Andrews song Pretty Belinda.
I'm sorry it's not much to go on. I will add more if I remember something.