His opinions would also be important as raising the youth justice age to include 17-year-olds was being investigated.
Mrs Tolley also acknowledged "the tremendous work" done by the outgoing commissioner Dr Russell Wills.
"He has never shied away from voicing strong opinions, always with the best interests of children in mind."
Dr Wills said the new commissioner brought "huge integrity and intelligence to the role". He said the Judge understood the needs of young people in the care and youth justice systems. "He knows what is working, what isn't and what a really good system would look like. He's the right appointment at the right time."
Dr Wills said he was proud of his team and that they would continue to deliver under Judge Becroft's leadership.
He was looking forward to working with Judge Becroft over the next two months before he takes over on July 1.