OFFICERS who missed chances to catch a double killer will not be investigated by the police watchdog.

Instead, Sussex Police will carry out a fourth internal review into their handling of a murder after three previous inquiries found no fault in how the case was handled.

The Independent Police Complaints Commission (IPCC) spent the last week deciding whether to look at how Sussex Police first investigated the deaths of Susan Nicholson and Caroline Devlin.

The force initially said the deaths were not suspicious and, as The Argus revealed yesterday, stood by this in three internal investigations. But last week Robert Trigg, who had been in a relationship with each of the women at the time they died in 2006 and 2011, was found guilty of Ms Nicholson’s murder and the manslaughter of Ms Devlin.

As the 52-year-old was sentenced to life behind bars, serving a minimum of 25 years, Assistant Chief Constable Laurence Taylor referred the force’s original handling of the case to the IPCC because it was “important” for public confidence that an independent review took place.

Yesterday an IPCC spokesman said the referral “did not meet the criteria for IPCC involvement” because it did not mention conduct or complaint which could help it decide if an investigation was needed.

Mr Taylor last night insisted this would be “robust” and “probing”, with a review of the investigations, how it handled complaints and that he asked West Sussex County Council to carry out an independent review into how public bodies worked together over the incidents.

Ms Nicholson’s parents, who had called in the IPCC three times during a six-year fight to have their daughter’s killer prosecuted, say they were told they would need to complain to the watchdog again for an independent investigation to be launched.

Elizabeth Skelton, 81, Ms Nicholson’s mother, of Goring, said the decision was “hurtful”, adding: “We’re not going to go back to the IPCC, there is no point. Another internal investigation by the police – what will that achieve?”