Lin and Megan died. Josie survived but suffered serious head injuries.
A year later, Michael Stone, who had a personality disorder and drug-induced psychosis, was arrested and charged with double murder and attempted murder.
Although an independent inquiry was completed by the end of 2000, its commissioners decided to hold back publication pending legal challenges by Stone. This meant the report was not published for another six years.
The report criticised the loss of a substantial part of Stone's medical records by the prison service and the lack of communication between different agencies involved in his treatment.
Why did it take so long?
An internal review of West Kent health authority, Kent county council and Kent probation service into the care of Michael Stone was completed in May 1998 by two independent mental health experts, consultant psychiatrist Dr Parimala Moodley and former senior psychiatric social worker and social services inspector Mary Hancock.
A few months later, in October 1998, Stone was convicted but shortly afterwards a prosecution witness admitted lying under oath, sparking an appeal.
In the meantime, an independent inquiry was commissioned jointly by West Kent health authority (now NHS South East Coast), Kent county council and Kent probation service. It reported in November 2000.
In February 2001, it was announced there would be a retrial following Stone's appeal. This resulted in a second guilty verdict and a life sentence in October 2001.
In April 2003, as the independent report was about to be published, Stone's lawyers announced that he was seeking a second appeal. He lost this appeal in January 2005.
Stone then tried to stop publication of the report by issuing proceedings for judicial review, on the grounds that it would disclose his private life.
In July 2006, the judicial review gave the go-ahead for publication, which finally happened in September 2006.
The joint action plan has not yet been signed off by the strategic health authority as there has not been enough improvement in the provision of low-secure services.
Director of nursing at Kent and Medway Partnership trust Peter Hasler said many problems were dealt with after the internal review.
He told hsj.co.uk: 'The action plan has largely been addressed now.
'General provision of the more forensic medium-secure end of services [medium-security locked wards] has improved hugely in the last 18 months. In Stone's day there were only 25 beds.
'He was asking for detox and didn't get it. A new facility opened four weeks ago to address this kind of issue.'
But he agreed that the report had taken too long to publish and admitted this had caused problems.