The Lord Chief Justice of England and Wales, Lord Woolf, was speaking publicly for the first time about the decision to free the two killers.
Robert Thompson and Jon Venables who were 10 years old when they abducted and murdered the toddler were released last year and granted anonymity.
During an interview with BBC Radio 4's "50 Years On" programme, Lord Woolf spoke about the right of criminals to be released back into society after they had served their time. It wouldn't bring baby Bulger back to life if one or other of those young men had been, in turn, killed. He used Thompson and Venables as an example.
In the interview, to be broadcast tomorrow, Lord Woolf said the rights of the pair had to be respected no matter what crimes they had committed.
"Those youngsters had committed very, very grave crimes," he said.
"They had been sentenced for those crimes but we ought not forget that although they committed those very serious crimes they were first of all human beings and secondly they were children. Children can do things when they are children that they would never do in their later life when they had matured and appreciated."
Lord Woolf played a key role in the release of the two killers when he ruled that they could be considered for parole after serving eight years in custody.
The pair, who are now 19, were freed on licence after the Parole Board said they were no longer a danger to the public.
Lord Woolf said the courts could punish people but they could never bring back victims: "We have to realise that everybody except those who commit the most, most serious crimes are eventually going to be let back into society."