Basic safety checks are still not being carried out by probation officers, according to their watchdog.
Justin Russell, the Chief Inspector of Probation, feared lessons were still not being learnt from previous failings in the sector.
He told reporters probation officers were still failing to carry out “basic domestic violence and child safeguarding checks” on offenders they were supervising.
Mr Russell said there were “reoccurring problems” with the probation service with “issues around competence” and it was a “mixed picture” as to whether department bosses were taking on recommendations to make improvements.
His comments came as he was questioned about the failings in the case of Joseph McCann.
The convicted burglar had been freed after a probation error, two months before he embarked on a cocaine and vodka-fuelled rampage in which he carried out a string of sex attacks on 11 women and children.
The National Probation Service (NPS) supervises around 105,000 high-risk offenders in total.
Union bosses claimed staff were working in “chaotic conditions” due to the size of their workloads in the South East and Eastern division of the NPS which supervised McCann.
Asked whether – in light of the inspectorate’s findings of high workloads and staff shortages – if the failings in the McCann case were inevitable, Mr Russell said: “If you are supervising 105,000 high-risk people then these things happen.
“It was a particularly horrible case which left a very large number of traumatised victims behind.
“It acts as an example of all the issues we have been talking about in terms of our inspection findings.
“It’s important that probation gets risk management right and actions and checked.”
The Ministry of Justice (MoJ) – which is responsible for probation – carried out an internal review after McCann’s review.
Of four probation staff in the South East and Eastern division who were directly involved in McCann’s case, one was demoted.
An earlier investigation resulted in one member of staff involved with McCann being dismissed and an agency worker’s contract being terminated for “poor performance”, although it was not understood to be directly related to the case.
Known as a serious further offences review, the detailed findings are not routinely published.
Asked whether the report should be made public, Mr Russell said: “I think that’s something the department should consider” but he agreed there was a “need for discussion around transparency”, adding: “I think there’s a strong argument for saying that there is a public interest in that once they have thought about how they manage that with the victims.”
The MoJ said discussions were ongoing as to whether the review into the McCann case would be released and victims were being consulted.