Michael Curtis' partner at the time, Oriwa Kemp, and Nia's cousin, Michael Pearson, were sentenced to three years and four months' jail and three years' jail respectively for ill-treating and assaulting Nia and two other children in the house.
Mr Sinton said if a person was responsible for ill-treating or neglecting a child, they should not be allowed to have another child.
If an animal owner ill-treated or neglected an animal then they could be banned from owning another animal for a time and Mr Sinton said that also should be the case for parents.
"If you can do that for an animal why on earth can you not do that for a baby?''
He said a mother found guilty of abusing her child should be given a court order preventing her from having an other child until they could prove they were a fit and proper person to be a parent. The woman should also be ordered by the court to take control or undergo birth control procedures. If the mother breached the court order she should be held in contempt of court and the baby taken off her. He said the man who got that woman pregnant should also be held in contempt.
He said some might think his suggestion was a breach of civil liberties but, he argued, what about the civil liberties of the child?
He said he was not a child abuse expert but had seen a lot of it during his years in the police.
Rotorua Mayor Kevin Winters said residents needed to speak out if they saw children being abused.
"You can't sit on your hands and do nothing. Nia [Glassie] was observed time and time again in a distressed state and no one did anything,'' Mr Winters said.
Dr Patrick Kelly, a paediatrician and clinical director of the child protection team, said in the documentary that any solution was quickly forgotten about until the next child died.
Mr Winters said Dr Kelly's comments, regrettably, had a ring of truth about them.
"They are a sad indictment of New Zealand society but one which many people in this community are working hard to ensure is not the case for Rotorua in the future.
"As a nation we have not taken this problem as seriously as we need to.
"It has to remain at the forefront until we no longer have such woeful statistics.''
Mr Winters said the Rotorua Safe Families group, which he set up after Nia's death, still met monthly.
"It has helped increase awareness across the community and has brought together a group of people committed to helping reduce these problems and to ensuring support mechanisms are available for keeping families safer.''
Rotorua MP Todd McClay was appalled at what he saw on the documentary and said Social Development Minister Paula Bennett was to release a paper tomorrow on vulnerable children and recommendations to deal with them.
"In almost every incident of child abuse or neglect in Rotorua a wider family member has been involved or a wider family member has not stepped in to protect that child and the white paper will put the child at the centre of the decision-making process.''
Ms Bennett will be in Rotorua on Friday to discuss the white paper with about 100 people who work with children.
"The Rotorua Safe Families campaign had done a lot of excellent groundwork but we need to take that and build on it and do more,'' Mr McClay said.