Mother Julia Trinne says she was 'ignored' by police while her husband murdered their son.

“I could see people in the station but they would not open the doors because it was not opening time,” Trinne said, continuing, “I understand protocols but when it is obvious something major is wrong you would think surely they would be able to realise this and act.”

At the same time, Janzow, who had a long history of mental health issues and had been diagnosed with depression and bipolar disorder, was murdering her son.

Luca Janzow. Source: Facebook / David Janzow.

When Trinne was admitted into the station, she says police were more focussed on the fact that she could not remember her husband's car registration than anything else.

Following his arrest, Janzow told police he had killed his son because he was a psychopath and believed his son showed signs of the same behaviour. The murder, he said, was an attempt to "save Luca from what was to come."

Janzow was ultimately found not guilty of murder due to mental incompetence.

Trinne, who now lives interstate, has said she plans to demand a coronial inquest into Luca’s death.