ALTHOUGH the IPLO is, in comparison with the IRA, a minute group, it is regarded as a particularly dangerous organisation - dangerous not just to others but to its own members. Brown is the fifth IPLO man to die violently in the past year.
Two of these were killed by loyalist groups while the other three died in incidents with overtones of internal feuding. And, according to the rumour mills of Belfast, one of the loyalists' victims was in fact set up by his own side.
The IPLO has killed seven people over the past 13 months, five of them Protestants shot dead in random sectarian attacks: the security forces seem relatively safe from its attentions. But the organisation has become linked in the public mind with drug dealing, racketeering and other financially-motivated crime.
Its most violent period came in 1986-87, when its deadliest feud led to a dozen deaths within the ranks of its parent organisation, the Irish National Liberation Organisation. That battle began when two factions became locked in a violent struggle for control.
Jimmy Brown was one of the leaders of the faction later to style itself the IPLO. He regularly briefed journalists during the fighting. The feud came to an end when one of his closest friends, Gerard 'Doctor Death' Steenson, was killed by the other side.
At that stage he was already a well-known republican figure. He was one of more than a score of people who were jailed on the word of the republican 'supergrass' Harry Kirkpatrick in 1985, but was released on appeal the following year.
Brown constantly complained about the 'supergrass' system, sending a flow of letters and articles to newspapers. He contested a by-election from prison as an 'anti-informer' candidate and appeared on television a number of times. In one speech in court he described the legal system as 'a farce, a harlot and a puppet'.
Earlier this year it became evident that a regrouping was going on within the organisation, with a number of former members returning to the fray after a period of inactivity. Signs of disagreements in the ranks came in early June, with several gun attacks and reports that houses in west Belfast had been ransacked.
There were continuing rumours of disputes over money, with reports that the IPLO existed at this stage not as one unified group but as a series of virtually separate gangs using the name as a flag of convenience.
Brown had latterly spent most of his time in Dublin, and is said to have returned to Belfast only at the weekend. One report has it that he was attempting to settle differences between various factions when he met the same fate as that suffered by so many of his associates.
Exactly a year ago Brown gave a graveside oration for a close friend, Martin O'Prey, who was shot dead by loyalists. A few days ago he inserted a commemoration notice for O'Prey in a Belfast newspaper; yesterday he unexpectedly joined him in the ranks of the republican dead.