The police “missed opportunities” to catch a double killer, who killed two of his partners over a five-year period, an independent inquiry has found.
Robert Trigg, 52, from Sussex, was convicted and jailed for life last year for both of the deaths but had initially been treated as a bereaved partner by the police on the two separate occasions.
Trigg was in a relationship with Caroline Devlin, 35, who was killed in 2006 and then with Susan Nicholson 52, who was killed in 2011.
Both women were killed in their homes, which are barely two miles apart in Worthing, West Sussex.
Ms Nicholson was suffocated by having her head forced into the bed and Ms Devlin's death was caused by a blow to the back of her head.
Foul play was ruled out following both deaths and Trigg, who has a history of domestic abuse against women, was initially treated as a bereaved partner rather than a suspect.
An inquest held in 2011 into Ms Nicholson's death ruled she died accidentally after Trigg claimed he inadvertently rolled on to her in his sleep while they were on a sofa.
Ms Nicholson's parents, Elizabeth and Peter Skelton, spent six years, and more than £10,000 of their savings, trying to convince the police to reopen the investigation.
They claim they were "ignored" and "failed" by the force and every public body tasked with holding them to account. They have continued to accuse police of a "cover-up".
Speaking to the Press Association from their home in Goring, 81-year-old Ms Skelton said: "Finally people are starting to listen to us. Finally we feel like we are being taken seriously.
"The more you look back at it all, the more furious you feel about how it was handled. They made fools of us. We keep thinking 'How could the police do such a thing?'
"It's very important for us that the full reports are made public so this can't happen to anyone ever again."
Mr Skelton, 83, said: "This confirms what we knew all along. They can't just say this was a mistake. We have been going on about this for six years. The evidence was pointing to this the whole time. Now we want to see the information they have."
Ms Skelton, who had a minor heart attack during her campaign for justice, added: "We want to read the findings in full and seek legal advice. We won't rest until all our questions are answered.
"Now is the time for the Independent Office for Police Conduct (IOPC) and (Sussex police and crime commissioner) Katy Bourne to step in and hold the police to account where they failed to do so before. We have been very unimpressed so far."
After Trigg’s conviction, police chiefs apologised, said the families would be offered compensation and that independent inquiries - carried out by neighbouring forces with which it shares resources - would be "without fear or favour".
A spokesman for the police force said: "Thames Valley Police have completed an independent review of the investigations. The review refers to potential missed opportunities and we have therefore referred it to the IOPC for their consideration as to the way in which they wish those issues to be progressed.
"We are truly sorry it took so long to get justice, and it is important we learn any lessons and provide answers for the families."
The IOPC said it is has not yet decided how to proceed or whether it would investigate the findings.
Agencies contributed to this report