They beat Mile Marceta to within an inch of his life. His crime was to want to return home - and to believe that the Dayton peace agreement allowed him to.
The Croat nationalists who beat him knew exactly what they were doing - the attack on Marceta, the leader of a group of Serb refugees who wanted to return home to Drvar in Croat-dominated north-western Bosnia, would send a signal to all potential minority returnees that the process of ethnic cleansing will not be put into reverse without a fight.
The challenge of protecting so-called minority returns is the key task facing Bosnia. Over a million refugees and internally displaced Bosnians have been unable to return to their homes. Overwhelmingly they come from areas where they were in a minority, having fled war or "ethnic cleansing".
With many majority returnees already resettled, the minority return process is now delicately getting under way and the international community has designated 1998 as their year.
They are going back to precarious, impoverished mountain villages or muddy tent camps beside the shells of flattened homes the length and breadth of this country, to neighbours who may still harbour murderous thoughts.
What happened to Marceta in April, and to others, cannot be ignored. Non-governmental organisations (NGOs) and international aid officials on the ground warn that in their haste to get rid of politically embarrassing refugees, European countries, particularly Germany, are forcing the pace of minority returns and jeopardising the whole process.
Because their security cannot be guaranteed, returnees are forced to join the 816,000 impoverished, internally displaced. And in many cases they take the homes of the displaced of other ethnic communities, so preventing their return.
And so relocation rather than return is becoming the unwitting policy of the international community and the explicit policy of the UN High Commissioner for Refugees, consolidating the effects of ethnic cleansing.
Under Dayton, refugees are entitled to vote in their home constituencies, so as to ensure minority political representation ahead of their return. And so it was that the exiles of Drvar elected Marceta their mayor.
At the time, and now once again, he was in internal exile, one of the 85,000 ethnic Serb refugees clogging up Banja Luka in Serb-controlled Republika Srpska, a city that is a microcosm of the complex inter-dependence of the problems throughout the country.
Some 60,000 ethnic Croats from the city are abroad or in the neighbouring Muslim-Croat Federation. They cannot return to their occupied homes in Banja Luka until those Serb refugees go home to Croatia's now deserted, bitterly contested Krajina province, or back to the Federation.
Croatia doesn't want the Serbs back in Krajina, preferring to settle Croats there instead. Yet 350,000 Croatian Serbs are refugees abroad, and unless a solution is found to their problem, Serb authorities in Republika Srpska are unlikely to facilitate other returns. Indeed, Bosnia's elections last weekend seem to confirm a hardening of attitudes, with increased support for extremist nationalist parties opposed to returns.
In June the Croatian government, under threat of EU sanctions, agreed to work on plans for a Serb return to Krajina. Few are convinced about its sincerity.
While SFOR, the NATO-led peace force, has kept an uneasy peace it has often proved unwieldy and inflexible in securing protection for the individual. Many of its contingents are unwilling to demonstrate the robustness proven to get results.
Property laws, supposed to be repealed under the Dayton accord, favour the rights of squatters. In the Federation, the laws have been amended but implementation is slow. Why should we move fast, Muslim and Croat administrators say, when change is barely mooted in Republika Srpska?
And often those who have returned with small resettlement grants from foreign governments or to homes rebuilt for them by NGOs have faced resentment from those in their own community who stayed and have nothing.
It is difficult, but international agencies and NGOs believe that small, agreed return programmes for minorities can gradually unleash a domino effect as returnees free up the homes of others and confidence builds.
Hans Steib of the Austrian NGO, Volkshilfe, stresses above all the need to solve the problem of the internally displaced before new mass returns from abroad. "If we want to rebuild the country we need more time," he pleads, echoing countless EU aid officials.
Yet Germany, in pre-election mode, has sent expulsion orders to tens of thousands of refugees which expired at the end of July. Bonn has told the UN High Commission for Refugees that it expects 150,000 Bosnians to go home, voluntarily or compulsorily, this year. So far some 40,000 have done so "voluntarily" with financial support.
By the end of hostilities in 1995, 1.3 million Bosnians had become international refugees. Of these, 208,000, for the most part majority returnees, had returned to Bosnia by the end of last year. Some 504,000 had acquired permanent status abroad, while 612,000 are still in limbo, awaiting repatriation as their temporary refugee status runs out.
There is no doubt that Germany took the brunt of the refugee exodus - 340,000 people, of whom 100,000 have since returned. The care of those remaining costs Germany £40 million a month.
The expulsions have been slow. The German court system only processed 1,000 case last year. But, more ominously, 40,000 refugees have been persuaded to leave "voluntarily" this year, assisted financially by Germany.
How voluntary such returns are is deeply controversial.
Gerald Knaus of the Sarajevo office of the International Crisis Group says Germany is using limited numbers of expulsions, under its cumbersome deportation system, to bully many more refugees to opt for voluntary return. Then, the refugees are told, they will be entitled to cash assistance and the right to visit Germany. If they wait until expulsion, they lose everything.
In Tuzla, returnees from Germany, unable to get back to their homes in Republika Srpska, queue for financial assistance. They are bitter. "We were voluntarily forced to return," said Nada Gusic.
In January the Council of Europe called on member states to "refrain from forced repatriation of refugees from minority areas", and, until recently, Bonn accepted that deportations of Croats and Muslims to Republika Srpska was not on. But in last few months, tens of thousands have received deportation orders to Republika Srpska. Almost all would be minority returnees.
And, although publicly unwilling to criticise the Germans, the Bosnia High Representative, Carlos Westendorp, acknowledges that premature returns only serve to complicate the situation on the ground.
Heinz Steib of Volkshilfe argues that in forcing the pace of returns, European countries are "passing the buck, solving their own electoral problems at the expense of a lasting solution in Bosnia".
The International Contact Group chairman, US Senator George Mitchell, warns that forced returns of minorities are likely to destabilise the more cooperative local administrations in the face of local majority pressure. Where returnees are put in jeopardy, they simply add to the numbers of internally displaced.
There is a danger in focusing criticism on countries which want to force the pace of returns, an ICG official argues. The international community must offer a realistic time-frame, based on the right of minority returns. If not, he says, Germany will find it difficult to resist domestic political pressure to increase the returns.
For such a strategy to be successful, he argues, it must be based on a radical reappraisal of approaches to the returnees' security, to the flexibility of aid distribution, and to the designation of misnamed "Open Cities".
Meanwhile, Marceta remains in internal exile and the dream of preserving a multi-ethnic Bosnia slips slowly away, victim of the international community's lack of political will and patience.