Around 400 people have left tributes and messages of sympathy in online Condolence Books for Diarmuid O'Sullivan and his father Tadg.
The funerals for two of the men killed in a dispute over farmland near Kanturk, north Co Cork will be held privately in line with Covid restrictions, at St Mary's Church, Castlemagner, at 2.30pm today.
They will be buried afterwards at St Brigid's Cemetery, Castlemagner.
The funeral of Mark O'Sullivan, who is understood to have been shot dead in his bedroom by his father and brother, will be held tomorrow and live-streamed at 3.30pm from the Church of the Immaculate Conception, Kanturk.
One of the online tributes to Diarmuid came from a former college friend Cathal Cadogan.
“Thanks for all the memories we've had together during our 4 years in CIT,” he said of their time at the Cork Institute of Technology.
He described the 23-year-old as “kind, friendly, a gentleman and - more importantly - a friend".
And he added: “It's been a pleasure. You'll never be forgotten.”
A couple who knew him when the 23-year-old worked at Burtons hardware store in Kanturk described him as “a very nice, pleasant and helpful young man”.
Offering “heartfelt sympathy” to his mother Anne “at this difficult time”, a former teacher said Diarmuid was “bright and conscientious”.
And they said it was “a privilege to have taught Diarmuid in Coláiste Treasa” in Kanturk.
A former classmate there said: “Rest in peace Diarmuid. I will hold fond memories of you!” Yvonne Connolly, from Kanturk, said Diarmuid was “a great friend” to her son Callum “all through school years”.
Tadg, 59, was described by Norma O’Brien in his online Rip.ie Book of Condolence as “a pure gentleman to work with”.
And she urged: “Look after your two boys and give Anne strength to live on.”
Séamus ó Ceallacháin offered his “deepest sympathy to Anne and extended families”.
And he said, referring to his school and the garage where he worked as a mechanic in Buttevant, he had “very fond memories of Tadg in Mallow Vocational School, and Greenhall”.
A Mary O’Connor, from Castlemagner, described him as “a gentleman”.
Carmel Lane, from Ballingarry, said she hoped his distraught wife Anne could find comfort from her faith “at this very difficult time”.
And she said: “My partner John Downes knew Tadg very well in Greenhall Motors and often spoke about him to me saying what a lovely gentleman he was.
Hundreds of messages have also been left on Mark’s online Book of Condolence with messages for Anne O’Sullivan over the shocking killing of her “beautiful son” Mark.
He was described as a popular figure with classmates at Coláiste Treasa, Kanturk, and at the University of Limerick and University College Cork, where he had studied law.
Edmund Ryan, from Limerick, described the 26-year-old law graduate as “a genuine, fun, considerate human being”.
He said he hoped time would help Mrs O'Sullivan to “find the reason to live every day and accept that this tragedy and responsibility for the great sadness and heartache all around you was not yours to carry”.
Former work colleague Ronan Murphy said: “[Mark] lit up the room with his infectious smile and was always willing to lend a hand whenever needed.”