The rainbow flag is flying for the first time above the Sydney Police Centre as officers reflect on the past 40 years ahead of this weekend's Mardi Gras.
Assistant Commissioner Tony Crandell says the NSW Police "got it wrong in the way they caused pain and harm to people who were standing up for their rights".
"That was very difficult as a police officer to watch how some of those people were treated in 1978," Mr Crandell told AAP on Monday.
The raising of the rainbow flag alongside the Australian flag at the Surry Hills complex symbolises unity with the LGBTQI community ahead of Saturday's parade, the assistant commissioner said.
"Our relationship is strong, we stand together shoulder-to-shoulder and we (need to) treat each other equally and with fairness".
The drizzling rain didn't dampen the spirits of those who turned up to see the colourful flag flying for the first time above the Sydney Police Centre on Monday.
NSW Police formally apologised to the LGBTQI community in 2016 for their actions during the first Mardi Gras march in 1978 when at least 50 activists were arrested amid reports of police brutality.
About 60 officers from the NSW Police force will march in Saturday's parade among transgender youth, a group that Mr Crandell says has one of the highest rates of attempted suicide due to bullying, harassment and discrimination.
"Transgender youth are very free and easy people and they love a party," Mr Crandell said.
At least 1000 on-duty police will also be scouring the Mardi Gras parade on Saturday as the terrorism threat level remains probable.
