Police dog Gage came to his aid, but was shot and killed by Smith.
Atalo was then shot by Smith as he tried to escape out a window.
Lamb had Gage on a lead, and did not realise until he reached the driveway that he was dragging the dog's dead body behind him.
Smith also admitted to charges of cultivating cannabis, a drug which he smoked daily. Police found 26 plants, 18 seedlings, and 400 grams of cannabis being dried, as well as scales and bags in his home.
The Press said a scraggly-bearded Smith stood in the docks during sentencing wearing wire-rimmed glasses and a fawn jacket. He was described in court as an intelligent man with a dry sense of humour.
Justice Whata said Smith had offended against people who were protecting the community and he had not expressed enough remorse to warrant reducing his sentence.
The offending had "profound and long-lasting consequences" for the police involved, the judge said.