On 14 April 1984, the body of a five-day-old baby boy was found on the beach at White Strand near Cahersiveen, Co Kerry.
The baby, subsequently named John, had been stabbed multiple times.
As the 39th anniversary of the discovery of the body of Baby John approaches, his parents have never been identified and his murder remains unsolved.
In January 2018, An Garda Síochána apologised to Joanne Hayes for the stress and pain she was put through in the original investigation.
Under that original investigation, on 1 May 1984, Joanne Hayes was charged with the murder of Baby John, charges which were subsequently dropped.
A tribunal later found that Joanne Hayes was not the mother of Baby John. Controversially, that tribunal merely described failings in the original garda investigation as "slipshod".
At the news conference in January 2018, at which they made their apology, gardaí also confirmed that Joanne Hayes could not have been the mother of Baby John, as the original investigation alleged.
Ms Hayes and members of her family have since received substantial compensation.
At the same time as gardaí apologised to Joanne Hayes, they also announced a cold case review of the investigation of the murder of Baby John.
They revealed that a full DNA profile for Baby John had been generated from samples preserved during the post mortem examination.
Investigating gardaí also reiterated their belief that the key to resolving the mystery about the murder of Baby John lay in Cahersiveen and the close surrounding area.
Later that year, in September 2018, RTÉ News revealed that DNA samples had been taken from a small number of people in the south Kerry area, as part of the garda cold case review.
The samples were taken voluntarily, at the request of investigating gardaí. Most of those who gave samples were women.
DNA sampling was continuing and remained a key focus of the cold case review, gardaí said.
Superintendent Flor Murphy, who led the cold case review, said more than 9,000 investigative hours had been spent on it, with 225 separate lines of inquiry being followed.
There were several appeals for people with information to come forward.
Also in September 2018, gardaí exhumed the remains of Baby John from the plot where he was buried at Holy Cross Cemetery in Cahersiveen and brought them to the morgue at University Hospital Kerry in Tralee for further examination.
The remains were reinterred at the Holy Cross Cemetery later that afternoon.
Gardaí also conducted door-to-door inquiries on Valentia Island as part of their investigation.
Since then, there has been very little public update on the progress of the cold case review.