Yesterday police charged a 29-year-old Mangere man, a former Orakei resident, with JJ's murder. The man will appear in the Auckland District Court today.
Last month, Detective Inspector Scott Beard said the four adults who were at the house when JJ died had given stories that conflicted with the findings of the post-mortem examination.
The Herald revealed Ms Lawrence was pregnant with her second child and Child Youth and Family was considering removing the new baby from her custody after its birth. CYFS also took the two infants who were living at the house into care.
Ms Lawrence moved into the house in Orakei with JJ in July. Before that the pair had been living in Tauranga.
Police turned to the public for help saying they wanted to speak with people who knew Ms Lawrence before she moved.
His father, James Robert Ruhe, was said to be "devastated" and "lost" when told of JJ's death.
Ruhe is in prison and did not seek compassionate leave to attend the toddler's tangi near Kaeo but the Department of Corrections allowed him to transfer to a prison closer to his family so they could support him.