A police watchdog inquiry into circumstances surrounding the death of Bijan Ebrahimi, who was wrongly branded a paedophile, has been completed.
Mr Ebrahimi was beaten to death near his Bristol home, despite making numerous calls to the police.
Files on a call handler and a dispatch supervisor have been sent to the Crown Prosecution Service (CPS).
The Independent Police Complaints Commission (IPCC) previously sent the CPS a file of evidence relating to three Avon and Somerset police constables and a PCSO.
An IPCC spokeswoman said in total 18 police officers and staff members, who had some involvement in the force's dealings with Mr Ebrahimi in the days leading up to his murder, had been investigated.
"I have provided the acting chief constable with a report detailing our findings as to whether or not those individuals have a case to answer for either misconduct or gross misconduct and should face disciplinary proceedings," she added.
The IPCC is also looking at police contact with Mr Ebrahimi dating back six years prior to his death.
This part of the investigation is continuing and Mr Ebrahimi's family, who say they are "desperate" for answers, are being regularly updated on progress.
Acting Chief Constable John Long of Avon and Somerset Police said he was "grateful for the thoroughness of the IPCC report".
He said his intention was to "address the matters of misconduct, the service failure that took place and the lessons to be learnt in a prompt, firm and direct manner".
Lee James, 24, who admitted Mr Ebrahimi's murder in July 2013, was jailed for a minimum of 18 years last November.
Stephen Norley, who admitted assisting an offender, was jailed for four years.

Ross Underwood, 30, was last seen at HMP Springhill at Grendon Underwood on Sunday during 08:00 BST roll call.
Underwood is described as white, well built with green eyes and short cropped hair.
Police said the man, who has links to Northamptonshire and Leeds, "should not be approached directly".
Det Insp Joe Banfield, from Thames Valley Police, said: "We are keen to speak to anyone who may know the whereabouts of this man and can provide us with information about his movements."
Prosecutors are to decide whether to charge two police civilian staff over events leading up to a murder.
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