Jaclyn Symes on Friday fronted the Yoorrook Justice Commission, which is examining injustices in the criminal justice and child protection systems.
Public drunkenness is set to be decriminalised in the state on Melbourne Cup Day this year, with the government ploughing ahead with the change despite objections from The Police Association of Victoria.
Ms Symes said the decision to not give police replacement powers was influenced by the experiences of other states, where residual powers meant decriminalisation didn't bring about "cultural change".
She acknowledged the government was aware there could be "unintended consequences" of the overhaul, including police charging intoxicated people with more serious crimes when the public drunkenness offence wasn't an option.
"We hope there's not the consequences of up-charging," Ms Symes told the truth-telling inquiry.
"I don't want to see people ordinarily charged with being intoxicated in public get a more serious charge to deal with that behaviour.
"We don't want to see that happen and that's an ongoing conversation with the police and the agencies on the ground and, indeed, people with lived experience."
The government would ensure effective oversight of the decriminalisation process, deploying a "guardian of the legislation" so Ms Symes didn't end up with statistics about what went wrong with the overhaul on her desk, she said.
The Victorian government committed to decriminalising public drunkenness at the start of a 2019 coronial inquest into the death of Yorta Yorta woman Tanya Day.
Ms Day was arrested for being drunk in a public place in December 2017 and later died after she hit her head on a wall in a concrete cell at Castlemaine Police Station.
Her death was preventable, a coroner found.
Ms Symes acknowledged police turned a blind eye to public drunkenness in the mainstream community and at sporting events including the Melbourne Cup.
"I don't think you will see many non-Aboriginal women who have been left by their friends on the side of a road drunk being picked up and put in a police cell. You don't see that," she said.
She acknowledged in her witness statement the justice system has both recently and historically been a "site of exclusion and oppression", and told commissioners structural racism with roots in colonialism persisted today.
Ms Symes agreed it was "universally accepted" the age of criminal responsibility should be at least 14, but said support systems including diversion and other programs had to be bolstered before the age could be increased to 14.
The government has agreed to raise Victoria's age of criminal responsibility to 12.
The government's commitment to ultimately raise the age to 14 by 2027 was also a promise "to build an alternative services model so that young people that are currently accessing the justice system for support services won't need to because there'll be alternatives", she said.
Yoorrook is the first formal truth-telling inquiry into past and ongoing injustices against Indigenous people in Victoria, as part of the state's treaty process.
Police Minister Anthony Carbines and Victoria Police Chief Commissioner Shane Patton are expected to give evidence at the inquiry on Monday.
