The veteran mob boss - jailed for 21 years in a UK court this week - is suspected of playing a key role in directing the murders of Noel 'Duck Egg' Kirwan, Trevor O'Neill and Martin O'Rourke. All three murders were carried out by hitmen linked to the Byrne Organised Crime Group - headed up by 'Bomber'.
He is also believed to have sanctioned the hits on his own cousins, Paul and Gerard 'Hatchet' Kavanagh, who were then shot by Kinahan Cartel gunmen.
Both Trevor O'Neill and Martin O'Rourke had no involvement in criminality and were collateral damage as 'Bomber' and his boss Daniel Kinahan waged war on the streets of Dublin.
The UK-based crime boss is also believed to have supplied weapons for two other murders linked to the Hutch-Kinahan feud.
Bomber is believed to have arranged for guns to be supplied to the killers of Derek Coakley Hutch - a nephew of Gerry 'the Monk' Hutch - and Jason 'Buda' Molyneux. The two Hutch associates were shot as part of a 'sub-feud' by criminals given weapons and logistical support by Bomber's network.
Sunday World can also reveal, Bomber's drug operation was preparing for massive shipments from Europe just ONE day after the funeral of his brother-in-law David Byrne, shot dead at the Regency Hotel.
Twenty-four hours after the 'Godfather' stood in mourning at St Nicholas & Myra Church on Frances Street in Dublin 8, his lieutenant Daniel Canning leased a new premises in the UK where drugs and guns would be delivered for transport on across England and Ireland.
In the weeks and months that followed he plotted a complex import-export plan, using modified machinery, legitimate transporters and suppliers and set up shadow companies to hide his network. But he also found time to kill.
The speed with which Kavanagh got back to business in the days after the murder of his wife Joanne's brother is a sign of his cold and calculated approach to the underworld, which he ruled for decades with an iron fist.
From his UK base,Gardaí believe that he ordered multiple murders, plotted assassinations and even provided weapons for others to kill.
The killings of homeless man Martin O'Rourke and tourist Trevor O'Neill, both shot dead in cases of mistaken identity, and the murder of The Monk's old pal Noel 'Duck Egg' Kirwan are suspected of having been carried out on his orders, while he also took a senior role in the plot to kill James 'Mago' Gately which backfired spectacularly.
The blood bond between 'Bomber' and Daniel Kinahan was cemented the day David Byrne took a bullet meant for the mob boss during a boxing weigh-in.
But already, two years previous, they had forged a murderous relationship when Kinahan came to him with 'intelligence' that his cousin Gerard 'Hatchet' Kavanagh was planning to kidnap one of Bomber's kids and hold them for ransom to the tune of €1million.
Although no evidence of such a plot was ever found, officers believe that Kavanagh gave Kinahan permission to kill Hatchet in Spain and later to murder his younger brother Paul in Dublin.
As the bloody Hutch-Kinahan feud exploded, they came together and like chess players planned their moves and decided who would live and who would die.
The fear he instilled in others was Thomas 'Bomber' Kavanagh's greatest power and he finely tuned his theatre of terror as a master weapons supplier and cold decision maker.
Those who worked with him knew to only speak when addressed and to always be on their guard against the ferocious temper that welled inside him. When the powerful fists came they showed no mercy and only the dumbest would try to intervene.
He held collections of weapons - like those found by the UK's National Crime Agency (NCA) between the bedside locker and the bed in his Tamworth master suite - and was never slow to use them. He regularly kneecapped or terrorised those who disobeyed his orders, mishandled his money or slipped up in any way.
Threats, torture and beatings were all to be used to exert power and control and most importantly everyone should know their place.
In Ireland and the UK he had a clear structure under him with each lieutenant having a detailed role and responsibility for logistics, weapons, drug trafficking or enforcement. Failures in any areas resulted in severe punishments.
Everyone within his ranks was controlled with violence and even more mature lieutenants, including former car dealer Lee Cullen and notorious Graham 'the Wig' Whelan, were regularly beaten for digressions. Cullen was so savagely beaten a number of times - once with a wheel brace - that he was admitted to hospital with his injuries.
While 'Bomber' enjoyed his power, he found himself feeling a touch of panic after he was arrested in prison in the UK, where he was serving a minor conviction for a pink stun gun found in his Birmingham home during a raid associated with the bigger case being investigated by the NCA.
It was Gardaí who had made the breakthrough into 'Bomber's' operation when they raided his weapons HQ in Dublin in January 2017 and seized an arsenal of guns and one very important document.
Unknown to Kavanagh, the document, a bill of lading for cargo from a transport company in the UK, was followed up by intuitive officers from the Garda's Drugs and Organised Crime Bureau.
It led to a legitimate UK company who had no idea they were transporting drugs and cash for Kavanagh's network and in turn resulted in a huge investigation known as Operation Hornstay, finely tuned undercover policing which carefully pieced together the chain of command in his group.
Snapshots of what was happening during the worst months of the Kinahan and Hutch feud show that Kavanagh was focused on two things; revenge and money.
In November Kavanagh, his father-in-law Jaws Byrne, his pal Declan Brady, aka Mr Nobody and Daniel Canning partied in New York when their first consignment of drugs made it through.
By December, four more multi million euro consignments landed safely. Kavanagh partied hard hosting a big bash at the Hyatt Hotel in Birmingham and weeks later Noel 'Duck Egg' Kirwan, the Monk's old pal, was shot dead in a sick final end of year push to increase the murders in Dublin.
However, on October 2, 2017 a consignment intercepted in Dover would lead Bomber to the dock of Ipswich Crown Court and to a massive 21-year sentence for his crimes.