This was irresistible propaganda: despite deploying huge resources against him, the gardai had failed to put him behind bars for a long sentence during a criminal career stretching back to a burglary conviction in 1960 when he was 11 years old.
Republican gunmen could claim to have succeeded where legitimate law had failed.
Last night the INLA said it was mistaken when it claimed initial responsibility. The group said it had planned to kill Cahill but the IRA had beaten them to it. The outlawed Ulster Volunteer Force meanwhile, moved to distance itself from Cahill, denying he was associated with it or played any part in its attempt to bomb a pub in the Irish capital in May.
Senior gardai had originally favoured the INLA claim. They knew a number of INLA members had arrived in Dublin recently and of a conflict between them and Cahill.
The conflict was reportedly triggered by the INLA's wish to set up a safe house in Cahill's south inner-city territory. A flat was subsequently burnt out, apparently on Cahill's orders.
Deeper frictions were perhaps caused by INLA members' determination to eat into Cahill's criminal earnings. The IRA, meanwhile, clashed with him in the 1980s when it supported strong- arm methods against drug dealers.
Gardai are now bracing themselves for a possible bloodbath, with the risk of further friction with the INLA, and with rival Dublin criminals keen to succeed Cahill as the gangland leader.
Yesterday morning Michael Watson, 39, was shot in the head, face and shoulder outside his home in the southside suburb of Ballybrack. Though no connection with the Cahill killing emerged, gardai have not established a motive. The wounded man was stable in hospital.
The scale of Cahill's 20-year crime spree - a raid on a jewellery factory, two large art robberies, lucrative wages snatches, bank and supermarket hold-ups - highlights Dublin's substantial organised crime network, which operates separate from the paramilitaries' fund-raising activities.
Cahill's desire to embarrass gardai permeated his criminal activity. While his gang were undertaking a major raid he would appear at his local garda station to have his driving licence verified, ensuring they would be his alibi.
A tough four-year sentence for possession of stolen goods 24 years ago may have shaped this prejudice early, along with a severe beating, including a fractured shoulder, he claimed gardai inflicted in 1977 when questioning him about a pounds 53,000 wages snatch.
This may have been reinforced by the death of his brother, Anthony, from a drugs overdose after alleged beatings in Curragh army camp, used for 'difficult' prisoners.
During heavy surveillance by a 60-member garda team in 1988, he told Magill magazine he was planning to enter the security business 'since everywhere we go the gardai go, we can offer an armed garda escort for the movement of large amounts of cash'.
Less amusing was his style of discipline. Cahill had a gang member nailed to the floor for allegedly siphoning off part of a pounds 2m gold robbery.
One of 12 children, several of whom also had criminal records, Cahill had an unorthodox family life. At 19, he married Frances Lawless, a fellow resident of an inner-city flats block, and had one family with her, then began a second with her sister. He moved daily between the two homes, one a new detached house worth more than pounds 100,000.
A non-drinker and non-smoker, his passions were cars, including a Mercedes, motorbikes, among them a valuable Harley-Davidson, and pigeons. He rarely went to pubs, though he did visit nightclubs.
His nickname 'The General', inspired by his obsession with detail in planning robberies and schooling gang members, was better known than his real name.
Typically, in his last high-profile operation in November, the kidnapping of the family of a banker, Jim Lacey, his lieutenants left a calling card on the bedside table - a box of chocolates and a card reading: 'And all because the Lady loves Milk Tray'.Reuse content