A retired school principal is attacked by two young toughs, an awful beating captured on surveillance cameras and aired on television for days in what has become Germany's equivalent of the Rodney King tape.
But in a country that has seen all too many neo-Nazi racist attacks against immigrants over the years, this video turned ethnic violence on its head: It was a young German-born Turk and a Greek attacking a 76-year-old ethnic German who had advised them to stop smoking on the Munich subway.
They threw him to the ground and kicked him, cracking his skull, excoriating him all the while, calling him a "pig" and a "German" with a particularly nasty adjective attached.
The attack last month transfixed the country, and opened the lid on anti-immigrant tensions that have skulked under the nation's politically correct surface for some time.
Now, the issue of immigrant crime has become the center of elections scheduled for today here in the state of Hesse. Gov. Roland Koch, long seen as an heir apparent to Chancellor Angela Merkel, has played the anti-immigration card with vigor in his bid for reelection, and stirred up a backlash among many voters who see uncomfortable echoes of Germany's Nazi past.
Not far into the campaign, Koch called for deporting non-Germans convicted of serious crimes, even those who may have been born in Germany. He also called for a code of public conduct that would include "German" values such as good manners, punctuality, respect for the elderly and speaking German.
"We have spent too long showing a strange sociological understanding for groups that consciously commit violence as ethnic minorities," he told the mass-circulation Bild Zeitung, which has embraced the issue with gusto.
That stance has bolstered Koch's popularity among the conservative Christian Democratic Union's older followers. But it has turned off many younger Germans deeply uncomfortable with the quasi-racist rhetoric, and has dragged Koch from a substantial lead to running neck-and-neck with his opponent, Andrea Ypsilanti of the left-leaning Social Democratic Party.
Around Frankfurt, many of Koch's campaign posters have had Hitler-like mustaches drawn on.
"It has to do with our history that there is never open debate on this issue. It's still, in a way, the mortgage of national socialism. Roland Koch is expressing what ordinary people think, things they talk about perhaps with friends, but you don't talk about it openly in national discussions," said Juergen Falter, professor of political science at Johannes Gutenberg University in Mainz.
Yet the topic is becoming unavoidable in cities such as Frankfurt, the financial heart of the European continent, where a stunning 66% of children younger than 5 come from an immigrant family.
The first waves of migrants from Italy and Turkey who came to rebuild the country after World War II were referred to as "guest workers," and it was assumed they would one day go home. Many didn't, and today millions of immigrants, mainly Turks, Russians and Poles, live in Germany and have the right to apply for citizenship, but their children are not automatically entitled to it.
What few, save Koch, have wanted to talk about is that many youths from immigrant backgrounds, saddled with poor educations because they couldn't advance through the sharply tiered education system without a mastery of German from an early age, have become involved in crime.
Elderly Germans often say they are afraid to take the subway after dark, fearful of a run-in with gangs of hoodlums, sometimes German, but often Turks or other minorities.
Although immigrants' share of crime is actually decreasing, it still is higher than their proportion of the population in many areas. In Hesse, about 27% of those arrested come from migrant backgrounds. But this reflects in part the fact that police often are quicker to arrest immigrant youths.
"Koch says the truth, he says what needs to be done: These criminals should be sent home," said Josef Schreiber, a 61-year-old carpenter who sat in the front row Thursday night at a rally here for the governor.
"We aren't the masters of our own house anymore," said Doris Horch, 67, a retiree.
Many young immigrants describe a society whose chief advantages, from good schools to high-paying jobs, go to ethnic Germans.
"I was actually not surprised about the campaign of Koch. What has surprised me is the intensity of humiliation that is brought on those who look different," said Fessum Ghirmazion, a 27-year old doctoral student in political science at Marburg's Philipps University, who sat listening quietly at a recent rally for the Social Democratic Party. "When I enter a room, people just look at me. It makes you feel like somebody who does not belong here."
Ghirmazion, who came to Germany from Eritrea at the age of 1, was allowed to enter the more advanced schools only against the vigorous opposition of his teachers, who advised him to remain with other immigrant students in the lower-standards schools.
A fifth of all migrant students drop out before earning their diplomas; the unemployment rate among migrants is double that of ethnic Germans.
"It's still expected from most immigrants who live here to behave as guests. That means to give up their own traditions and to assimilate," said Yilmaz Memisoglu, a 71-year-old retired electrical engineer who immigrated from Istanbul in 1961. He now is president of the Foreigners Advisory Council of Hesse.
"There were lots of hopes by the immigrants, especially with the talk about boosting German-language teaching and so on, but this election campaign has kind of spoiled all these hopes," Memisoglu said.
"Let me say one thing: Integration is possible only with confidence. And this confidence is gone."
At Thursday night's rally, more than 3,000 of Koch's supporters filled the square outside Frankfurt's ornate old opera house as a Dixieland band played the "Battle Hymn of the Republic." There were also at least 500 protesters, most of them young ethnic Germans, carrying banners reading "Anti-Fascist Action" and shouting "Nazis out!"
Koch, seemingly undeterred by his plunge in the polls, stayed on message.
"You yelling youths without any manners, you are not the majority here!" he proclaimed.
"We have to deal with the issues of integration and internal security, especially here in Frankfurt, where 66% of the children born have a migration background -- we have to talk about that," he said. "And when we see the problem of the violence, and when we see that immigrants are perpetrators of half the crimes, then we have to discuss these problems."
On stage with Koch was Merkel. The election is a litmus test for her awkward grand coalition in Berlin, which includes the Social Democrats. The chancellor opposes Turkey's bid to enter the European Union, and won applause at a recent party conference for saying that mosques should not be taller than churches.
Merkel has tried to calm the controversy, insisting that juvenile crime does not have a single ethnic dimension.
"It doesn't make sense to have a good public transport system if people don't want to use it after dark," she said at the rally. "Integration is a key issue for the future of this country. And at the same time, we have to talk about how to punish crimes like what happened in Munich."
Juergen Froehlich, a juvenile court judge, doesn't deny that a big proportion of those who pass through his courtroom are the children of recent arrivals. But deporting them is no answer, he says.
"The fact that we haven't managed to educate them into decent people doesn't mean it's the right thing to send them back to Turkey," he said. "They were infected here. And we have to heal them here."