The petition aims to decline parole eligibility for those convicted of the murder of police officers.
Matthew Hunt, who was killed in the line of duty, will be honoured at Tuesday's service.
The 24-year-old was granted interim-name suppression at his first appearance in June.
His mother said he had everything "to live for".
The murder-accused has also kept his interim name suppression during the brief appearance in the High Court in Auckland.
His colleague Constable Matthew Hunt was killed during the shooting.
The charge carries a maximum sentence of seven years.
Her daughter, who is believed to be arriving on Monday, will also need to complete her 14 days of managed isolation.
"When you lose one of your own, you start to second-guess what you could have done differently."