Police found a man in his 40s, his wife, who was in her 30s, and their three sons, aged 13, 11, and six, at the County Cavan home dead.
Teacher Alan Hawe, from Barconny, in Ballyjamesduff, stabbed his wife first before knifing his three boys at the family home this morning.
Local man Mr Hawe, who is well known in the area, is believed to have turned the knife on himself after killing his partner and three boys.
Heartbreaking images emerged this evening as several coffins were removed from the house and placed into a waiting convoy of hearses.
A source said: “Alan Hawe was well known in the area and was well respected because of his work in the school and also in GAA circles.”
In a press briefing at Ballyjamesduff Garda Station, Assistant Commissioner John O’Driscoll said two of the deceased were found in a downstairs room and three were found upstairs.
A Garda spokesman said: "The Garda investigation is ongoing but at this stage we are not looking for anyone else in relation to the deaths."
At a press conference, Assistant Commissioner O'Driscoll added "We believe all the answers are in that house.
"We are working along very definite lines of inquiry.
"One person in that house may have been responsible for the death of the others."