The police watchdog has completed an inquiry into the Stephen Port serial killer case and passed its report to the Metropolitan Police.
The Independent Office of Police Conduct (IOPC) has been investigating 17 officers.
Port was sentenced to a full life term in November 2016 for murdering four young men in London.
Police ignored chances to catch him earlier, with the deaths not treated as murders until weeks after the last one.
IOPC regional director Sarah Green said: "A file containing all relevant evidence alongside my opinions as to whether or not any officer should face disciplinary proceedings, has been passed to the Metropolitan Police.
"We have written to the representatives of the families of Stephen Port's victims and the officers under investigation to update them."
A spokesperson for Scotland Yard confirmed the force had received the report.
"We are considering its contents and will respond to the IOPC shortly," they said.
Seven of the officers were interviewed under gross misconduct notices and ten under misconduct notices.
Sixteen of them provided "no comment" interviews and instead submitted prepared statements.
One officer, who was interviewed under a misconduct notice, has since resigned from the force.
Between June 2014 and September 2015, Port murdered Anthony Walgate, 23, originally from Hull, Gabriel Kovari, 22, from Lewisham, Daniel Whitworth, 21, from Gravesend, Kent, and Jack Taylor, 25, from Dagenham, east London.
A pre-inquest review into the four deaths took place at on Tuesday at Walthamstow Coroner's Court.
In November last year, the High Court quashed the original inquests into the deaths of Mr Whitworth and Mr Kovari, paving the way for all four victims' inquests to be held together.
Assistant Coroner Dr Shirley Radcliffe will decide whether the inquests should be moved out of the eastern area of Greater London, where the original inquests into the deaths of Mr Whitworth and Mr Kovari took place, which is the wish of the victims' families.
Dr Radcliffe said she will inform the interested parties of her decision by 17 September.
Families of the four victims have launched a crowdfunding campaign to cover their legal costs during the inquests.
Following the hearing, Mr Taylor's sisters Donna and Jenny said they were "pleased the process has started and we hope we're getting closer to the many unanswered questions we have."