John Scott, QC, spoke out after the Scottish Government published proposals to raise the threshold of anonymity for criminally accused teenagers from age 16 to 18.
It is a move that would halt the identities of offenders aged 16 and 17 from being revealed.
The mother of Luke Mitchell, who was found guilty of murdering his girlfriend, has backed the proposal, claiming her son had been tried in a court of public opinion at the age of 16.
Meanwhile, Labour and Conservatives have condemned the proposals set out in the Victims and Witnesses Bill, with Tory chief whip John Lamont describing the move as ludicrous and prioritising the rights of criminals.
However, Mr Scott, chairman of the Howard League of Penal Reform in Scotland – defender of Craig Roy who murdered schoolboy Jack Frew aged 17 – said the move was necessary.
Mr Scott said: "Someone who is 16, 17 or 18 who is getting into trouble may well not be the same person they will be in 10, 15, 20 years' time. But if they are named and subjected to a lot of publicity, it can have a branding effect that follows them around and makes it far more difficult for that past mistake or serious misjudgment of childhood to be left behind and allow them to be a fully contributing member of society."
Mr Scott added: "When you are talking about children and young people who offend part of what we want to look at is future risk. If you make it much more difficult for them to escape the consequences of what they have done, you are making it much more likely that they are going to re-offend. You are then part of the problem."
Under the proposals, sheriffs and judges will retain the dis-cretion to name those under 18 if they feel it is in the public interest in a move that would bring Scotland in line with England and the majority of EU states.
Mrs Corrine Mitchell, who is campaigning for her son's conviction to be overturned, said: "My son was tried in the court of public opinion because everyone knew his identity.
"To be honest, I don't see why anyone should be named before they are convicted. But it's especially crucial for young people."
Morag Driscoll, director of the Scottish Child Law Centre, said she welcomed the proposals.
The vast majority of crimes committed by 16- and 17-year-olds were far less serious than murder but the consequences of the offence were likely to have a disproportionate impact on the young person, she argued.
Ms Driscoll said: "The lawyer's question is always 'What is the harm we are trying to prevent?' If it is to protect young people having a disproportionate limit put on their life chances then perhaps it is a very reasonable measure."
She added that young people were offered extra protection before the age of majority, such as being unable to buy alcohol, cigarettes or get a mortgage.
However, Brian McConnachie, QC, chair of the Faculty of Advocates Criminal Bar Association, argued that people had a right to know who has been convicted of a crime.
Labour justice spokesman Lewis Macdonald said it was inconsistent that the SNP should argue 16- and 17-year-olds should have the vote but not be considered an adult on the conviction of a crime.
He said: "Courts already have the discretion to prevent naming of the accused, and ministers have yet to show good reason why this should change."