Today, Sergeant Paul Robertson said the parents were calm but clearly worried the evening Ihaka died.
Constable Paul Kidd was at the police station with Taylor when they received the call Ihaka had died. He said Taylor was initially very upset, and sobbed - then remained very quiet.
Detective Elliot Western was the first to interview Stokes after her son had died.
Defence counsel Phil Shamy said when Western interviewed Stokes, the police were of the view that there were two people in the house - so it must have been one of them.
When Western asked Stokes whether she had caused any injury to the child, she replied: "Not that I know of."
The detective asked for a more definite answer, and she replied: "I don't want to say no because it makes Troy look really bad."
Western then said: "Let's just think of you being the mum of that child right now and no one else in the world, okay?"
Her answer was then a straight "no".
Stokes yesterday took the stand to repeatedly deny having anything to do with Ihaka's death.
Taylor also denies assaulting the child on July 2, 2015 - the day before the alleged murder.
The trial, before Justice Cameron Mander, continues.