Ms Manno’s mother Aggie Di Mauro said Celeste had gone to police twice about her concerns. The first time she was told nothing could be done.
The alleged harassment continued and she went to police for a second time.
Ms Di Mauro said it was taken more seriously due to “appalling, disgusting” messages on social media and an interim intervention order was put in place.
There was an alleged breach of the order several months later and Mr Sako was arrested, charged and released on summons, Ms Di Mauro said, but the family was advised to keep the intervention order in place.
A petition to strengthen laws around stalking sparked by Celeste’s death was tabled by Justice Party MP Tania Maxwell in State Parliament earlier this month after it gathered more than 8000 signatures.
Ms Maxwell said the enforcement around stalking and intervention orders were “an absolute disgrace”.
With Simone Fox Koob