His mother Melissa was charged with his manslaughter 11 months after a police investigation that included installing recording devices in her home.
The West Australian Supreme Court was told Bulloch had no memory of what happened to the child, whose cause of death was a traumatic brain injury.
Bulloch had been using methamphetamine and cannabis and traces of drugs were found in the baby’s system, but that had not contributed to his death.
Justice John Chaney said there was no doubt Bulloch’s drug use was a major factor in her offending.
He said the victim was extremely vulnerable and dependent on Bulloch for his safety, but she had subjected him to a significant degree of violence and trauma.
Mother tried to blame others
Justice Chaney said there had been a “long delay” in Bulloch accepting responsibility for what she had done, but he was satisfied she now had “some degree” of remorse.
However, he said aggravating factors of the crime included Bulloch’s voluntary use of drugs and her attempt to deflect responsibility for the child’s death on other people.
An earlier court hearing was told Bulloch had suggested her partner, his mother or a “good Samaritan”, who had helped her when she ran out of fuel, could have been involved in the death.
There was also evidence that in the baby’s short life, Bulloch had blown cannabis smoke in his face to calm him down, that she had left him in a car unattended and that she had been heard swearing at him and abusing him.
After the child’s death, she was secretly recorded saying somebody had shaken the child to death and she was sorry for killing him.
The court was also told Bulloch suffered a number of mental health issues and had been diagnosed as having post-traumatic stress disorder and a personality disorder.
In a letter to the judge, Bulloch said she could “acknowledge and take full responsibility for this tragedy” and her son “deserved to live, love, laugh and experience life”.
While she could not “take back what happened”, Bulloch said she would “forever live with this guilt, shame and despair”.
Bulloch, who initially pleaded not guilty but later changed her plea, will have to serve six years before she can be released. With time already served, she will eligible for release in December 2020.