Despite preparing for their first baby together, a pint-sized mom- to-be became enraged and killed her unborn baby boy's father because he came home late, friends and authorities said.

Lina To, 16 years old and 8 1/2 months pregnant, stabbed Rocky Ham, 19, once in the neck and twice in the chest - killing him when she plunged the knife into his heart early Sunday, police said.