Hawe family death probe police not looking for anybody else in connection with shocking events in Ballyjamesduff
Garda believe "all the answers are within the house" as they investigate the deaths of a married Irish couple and their three children.
Assistant Commissioner Jack O'Driscoll confirmed that a number of objects found in the house at Ballyjamesduff are under examination as officers piece together the tragic family's final movements.
He said: "We are not looking for anybody else.
"We believe all the answers are within that house."
"The most likely scenario is that one person in that house may have caused the death of others.
"All the circumstances will be explored."
It is suspected that mother and primary school teacher Clodagh and her children Liam (13), Niall (11) and Ryan (6) Hawe were all murdered by their father Alan Hawe before he took his own life at their home in Oakdene, Barconey, Ballyjamesduff, Co Cavan.
Assistant Commissioner O'Driscoll described the five deaths as "a very sensitive case".
"Nothing had happened prior to this grim discovery this morning which gave rise to anybody, including the Garda Siochana, that anything was untoward.
"The family were engaged with the community and seen yesterday (Sunday). None of the activity and the interaction with other people gave rise to any suspicion," he said.
The Garda is working quickly on the case.
"We have identified everybody we believe can be of assistance in this matter. When we have spoken to all of those people, we will have more answers," the senior officer said.
Gardai in Monaghan were alerted to the deaths at the family home at around 10.45am yesterday.
"Having called to the house in question, two members of the force called to that house and entered the house and made the grim discovery.
"On finding five deceased people, immediately a full investigation has been launched," Mr O'Driscoll said.
"There is no evidence that a firearm was used. In the course of a technical examination, which has been continuing for some time, we will have a more defiant answer to the exact cause of death.
"A number of objects that have been found in the house are subject to the detailed technical examination.
"Until that examination is complete, we are not in a position to say the exact cause of death," he said.
"There are family members who have a very difficult time to deal with.
"We need to speak to them and discuss the circumstances with them.
"Over the coming days more information will be revealed," he added.