The funeral of tragic Mari (5) will take place on Tuesday. She died in a blaze which ravaged her home at Termon Road in Boyle, Co Roscommon, in the early hours of Monday.
Her father, Richard suffered severe back injuries while trying to save his three daughters, Mari, Naomi and Lauren.
An accusation of a love affair is believed to be the reason the notorious gangster carried out an arson attack which resulted in the death of little Mari.
But no one who lived at the gutted house at Termon Road in Boyle was the focus of the arsonist's rage.
A suspect was picked up by gardai in the Sligo area on Wednesday afternoon after a massive 48-hour manhunt focused on the north-west of the country.
The man is the chief suspect in the gangland murder of low level Sligo criminal Sam Smith (23) who was shot dead in December, 2005.
He is also believed to be a very close associate of notorious Sligo criminal David Lynch (39) who was murdered in January, 2008.
The suspect has convictions for burglary and possession of a firearm and he is part of a criminal gang based in the Sligo area. He is understood to have given a woman "a severe beating" in the days before the arson attack -- this woman also did not live at the house on Termon Road.
It has emerged that tragic Mari died when she climbed back inside a burning building after seeing her father fall from the roof while attempting to save her and her two sisters.
Mr Connolly (27) has revealed how he battled to save his little girl and his devastation on learning she had died.
Mr Connolly said he wanted people to know he did not jump from the house with two of his daughters but that he "tried to save the three of them".
He was looking after the girls, Lauren (8), Naomi (6) and Mari, while their mother Teresa Kane -- his former partner -- was in hospital giving birth to twins.
At 2.30am on Monday, he awoke in his upstairs bedroom to find the home on fire and quickly got his three daughters out of bed.
Flames were reaching the top of the stairs and the rooms were filling with smoke. He took all three children to the back of the house and brought them onto the roof.
Mr Connolly planned to break his neighbour's window and help the girls through the opening.
But he lost his grip and fell 12ft to the ground, hitting his back on concrete steps below and injuring himself badly.
Mr Connolly said he then "screamed at Lauren to jump" and land on top of him, which she did. Naomi did the same thing and he told Mari to jump as well.
"But I couldn't see her," he said.
He kept screaming for her to jump but she was nowhere in sight. Richard believes Mari was frightened and climbed back in through the open window.
He said he would never know why she didn't jump. "That will be with me forever," he said.