The chairman of an inquiry into public services which came into contact with a double killer and his victims before they died said lessons will be learned if mistakes were made.
The domestic homicide review led by the Safer West Sussex Partnership will determine whether staff were aware of Robert Trigg's violent past behaviour but could have done more to protect his victims Caroline Devlin and Susan Nicholson.
Trigg's trial heard how he and Ms Nicholson met at the West Sussex County Council-funded St Clare's alcohol rehabilitation centre in Worthing. Her parents claim staff could have protected her.
Arthur Wing, a former member of the Advisory Council on the Misuse of Drugs, as been appointed chairman of the inquiry and will write the final report.
Speaking to Press Association, he said: "In this case there may have been other concerns about the perpetrator's behaviour that could have come to the notice of agencies and we are wanting to ensure that if they did, we will pick up any learning from that."
The complex inquiry is broader than the statutory requirement and spans nearly a decade so will take a considerable period of time to complete, he said.
The panel met for the first time in October and commissioned internal reviews from organisations like the council.
They will all be asked what they knew about the case, their contact with anyone involved and what they did to "manage any risks identified".
A draft report is expected in the summer but is not likely to be finalised and published until the end of the year.
Mr Wing said: "I'm confident we will do the best job we can. The fact we are talking about work carried out up to 10 or more years ago means we may not find the answers to every question we would normally ask but we are going to work with the agencies to make sure any lessons that we can identify [are put] into practice in the future.
"[The report] is not going to be delayed unduly but we also have to make sure we uncover anything that is there to be uncovered that's of relevance.
"I recognise any report is not going to be the end of the story for the families of the victims. These tragedies will live with them forever.
"What this is saying is agencies do care, they do want to learn, they do want to understand how these terrible tragedies occur so that staff now are as well trained, as well briefed as possible to support potential victims and manage potential perpetrators."
Safer West Sussex Partnership confirmed it commissioned the report, which will be anonymised in line with national guidelines set by the Home Office when it is published.
Because of this panel members cannot refer to specifics of the review when discussing it publicly.
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