More than 1,000 messages have been left on an online book of condolences for Mark O'Sullivan ahead of his funeral today.
The 26 year old was found shot dead at his home in Kanturk, Co Cork on Monday in a suspected-murder suicide.
His brother Diarmuid and father Tadg O'Sullivan were buried yesterday.
Their funeral service heard that a darkness has enveloped the O'Sullivan family and the local community.
Ralph Riegel, Southern Correspondent for Independent News & Media, says Gardai are remaining tight-lipped about the nature of their investigation: