Chesty Morgan was an otherwise normal-sized woman with a 73 inch bust, and in this film she plays Crystal, a woman hell bent on tracking down the men who killed her lover. She seduces and drugs them, then disrobes to smother them with her breasts (the titular “deadly weapons”). Chesty herself is dubbed and not a great actress, the real stars here are her breasts, which are veiny and horrifying and sag down to her knees.
This is just straight out exploitation with little regard to good acting or plot, and mildly amusing just for the novelty factor. The deaths in particular are hilarious, with the men being unconvincingly smothered under the bulk of the breasts. A ridiculous sleazefest.