Garda Commissioner Drew Harris has confirmed reviews of the investigations into the murders of Tina Satchwell and Michael Gaine.
He said he accepted that, "in hindsight", it may seem "very obvious" where Ms Satchwell's remains were located - at her home in Youghal, Co Cork.
A report on the investigation will be furnished to the Minister for Justice and the Policing and Community Safety Authority, according to the commissioner.
He also said that gardaí are subjecting the inquiry in the case of Co Kerry farmer Michael Gaine to a peer review.
Mr Harris said there were lessons to be learned from homicides, which begin as a missing persons' cases.
The commissioner said he understood why concerns had been raised about the failure to discover Ms Satchwell's when the home she shared with her husband and killer was first searched in 2017.
Richard Satchwell was jailed for life earlier this week for murder.
Commissioner Harris said the investigation harvested a huge amount of information in 2017 in relation to finances and communications and a forensic scientist found no blood splatters in the search.
However, he pointed out that the initial investigation and search was "hamstrung by the lack of information in comparison to the subsequent investigation of this matter".
Ms Satchwell was a victim of coercive control and isolation, he added, and there were "very few others we could speak to what her life was like".
Mr Harris said it was very early for him to make a judgement on the adequacy of the initial search as he wanted to see the papers and review the case first.
Gardaí have seen a real pattern around this in recent years, the commissioner said, and they want to be sure that they have an investigative mindset in relation to a crime having been committed around a missing persons' report.
He said they were subjecting the Michael Gaine investigation to a peer review because there is "learning around those who would commit crime and then dispose of the body and are often successful in disposing of the body".
Gardaí have reviewed all missing persons' reports and found no other homicide cases, Mr Harris added.
The commissioner was speaking at the graduation of 120 new gardaí in Templemore, Co Tipperary.
'Missed opportunity' not to use cadaver dog in Satchwell search
A retired detective inspector and senior investigating garda said he believed it was a "missed opportunity" by the original investigating team to have searched the Satchwell home without bringing a cadaver dog in.
The animals are specially trained to detect human remains.
"A cadaver dog would have picked up on that straight away," Pat Marry told RTÉ's Drivetime.
"The warrant that they had, it's what's called a Section 10 warrant, they were looking for evidence of blood ... they didn't find that.
"Why would they find blood if he [Richard Satchwell] suffocated her or strangled her."
Mr Marry said the review of the case is welcome as lessons may be learned from its findings.
"But there are dozens of retired detective inspectors and detective superintendents who would have investigated murders in the past.
"As far as I am aware, none of them, including myself, have ever been asked back to the Garda College to give a lecture or a talk on murders or of things that may be of benefit to up-and-coming detectives."
The experience that he and others accrued over the years has never been "recycled" back in to the gardaí, he said.
Mr Marry also said that he had a Dáil question raised about why An Garda Síochána does not examine bringing back retired members on a contract basis - "people with track records and ample training" and deploy them on missing persons cases and unsolved murders.
"They do it in every other European country," and in the PSNI, he said.
