Mr Riina was on the run from the police for twenty-three years but was finally arrested in January 1993.
I was living in Italy at the time, and the capture of Riina was hailed as a great success in the fight against crime. The fact that he had evaded capture for so long had been emblematic of the Italian state’s helplessness in the face of the Mafia.
Riina’s arrest probably did mark a turning point in the battle against the mafia in Sicily.
But questions remain to this day. Riina was not on the run or in hiding in the usual sense of the word. There were no recent photos of him, so no one knew what he looked like, but he was living normally at home in Palermo, not in some mountain hideout, nor moving from place to place. He was, as they say, hiding in plain view.
And it has often been assumed that he was able to do this with the connivance of the authorities: in other words, Riina had significant backing from politicians in Rome.
When you think of it, it is pretty hard to hide in the modern world. We can all be traced by our bank accounts, by our travel arrangements, by our internet use.
Presumably Riina, like Osama bin Laden in a later case, used an elaborate series of proxies.
One assumes too he had no bank account in his own name, and was used to using large amounts of cash.
But if you or I were suddenly to disappear, to go underground, it would be practically impossible, without the help of a network of friends.
Most of us know this from having watched, for example, the Bourne films.
As for setting up a new identity, getting a passport in a false name, that too would be pretty hard.
Most of us would not even know how and where to begin.
Salvatore Riina did it, but he was a mafia boss.
Thus it is hard to believe that an elderly ex-monk could do what Laurence Soper has done, namely disappear without trace.
He is, you may remember, the former Abbot of Ealing who skipped bail and disappeared before he could be charged with serious crimes.
He is thought to be hiding in Italy.
There are one or two facts about the Soper case that make you wonder.
He was interviewed by police in England, but the police did not photograph him, and they did not confiscate his passport.
There are no recent photographs of him ( a bit like Salvatore Riina) and there is also confusion about his age: it seems that he is 68, but other sources mention him being in his eighties.
If he is living quietly in Italy, this raises important questions.
Has he a bank account in his own name?
Is he living under an alias, and if so, how did he acquire it?
Who is helping him?
Or has he been able to disappear relying purely on his own cunning?
This seems doubtful: you cannot do anything in Italy without an identity card or passport.
You cannot have someone to stay in your house for more than three nights without advising the police of it.
There are numerous rules and regulations, all of which were flouted by Riina, but which Soper might find harder to avoid.
Perhaps he is not in Italy at all.
But someone must know where he is, surely.
And one day he will be caught.
We should pray that he hands himself in.
Meanwhile, his continuing disappearance raises some pretty awkward questions, not least for the police who let him slip through their grip.