THEIR legs were too short to touch the floor in the courtroom, and they whiled away the hours in front of the judge with a stack of colouring books. Could these two young boys, aged seven and eight, really be the culprits in the brutal murder of an 11-year-old girl? The Chicago police said yes. In an indictment that shocked every American - even in a country which had thought itself immune to news of violent crime - the two boys were charged with beating the girl, Ryan Harris, to death with a rock, then suffocating her and leaving her dead with her panties stuffed down her throat. The boys, the police said, had confessed to the July attack, saying they killed Ryan because they wanted her bike. The incident induced waves of angst in newspaper columns and on radio talk shows, as citizens agonised over what was happening in an America where boys barely able to tie their shoe laces could perpetrate such an evil act. On the heels of several school shootings, it seemed social deviants were getting younger by the week. But then results of forensic tests of Ryan's underwear came back from the labs, showing traces of semen. The girl had clearly been sexually assaulted - an act beyond the pre-pubescent suspects, who were allowed to go free. Overnight, the tale of a gruesome primary school murder has been transformed into an issue of race and of the police's role in keeping the law in one of Chicago's grittiest black ghettos. The police force has been thrown on to the defensive by allegations it metes out justice differently to blacks - no matter how young - than it does to the white inhabitants of the city's more salubrious suburbs. Questions are now being asked about how charges could have been brought based solely on confessions elicited from the two boys in an interview in which no parents or lawyers were present. The answer, local residents suspect, is simple: that white cops are more than happy to believe a seven-year-old could carry out a brutal crime - if he is black. 'The way the police do business in the black community is totally different,' the boys' lawyer, Catherine Ferguson, said. 'In a white middle-class community, parents would have broken down the door and said 'let me in there'.' Fingers are pointing at the chief detective in the case who, in a similar case in 1993, had an 11-year-old convicted of murdering an elderly woman solely on the basis of a confession - despite evidence suggesting he was not nearly strong enough to have done it. The police have responded to the public relations crisis by reviewing their juvenile procedures to avoid future cases of underage suspects being coerced into making statements. But meanwhile, Ryan Harris' killer remains at large. 'The residents are living in terror, both because there is a paedophile still roaming the streets and because they feel that the police have no real intention of protecting them,' says Robert Starks, a Northeastern Illinois University social science professor. One of the criticisms levelled at recent immigrants is that they do not try to assimilate into mainstream society. Since every American is by definition the descendant of immigrants, such critics feel they have the right to pass judgment on a newer generation of immigrants who do not seem as committed to the national identity as their forefathers were. But according to a new study, assimilation is not necessarily good for one's health. Evidence suggests that immigrant children - no matter how much poverty they escaped from - become less healthy after a few years in the United States. It seems that while the land of plenty might be good for the wallets of immigrant Mexicans or Chinese, having more money often means it is spent on stuff that is not good for you - and more often than not, it is the food. In short, immigrants' children are dropping their rice bowls and fresh vegetables for the Big Mac - creating a kind of working class of unhealthy children. 'The McDonaldisation of the world is not necessarily progress when it comes to nutritious diets,' said Ruben Rumbaut, whose research fuelled the study by the National Research Council and the Institute of Medicine. The study notes immigrant cultures place more value on unprocessed foods such as grains and vegetables, even though they might have less money. Another theory for the phenomenon is the fact that immigrant families often have a strong moral or religious grounding which keeps children under greater control and frowns upon alcohol and drugs; after a while in the US, however, such disciplines tend to weaken. Mothers could be another key to the puzzle; amazingly, there is a lower mortality rate among the babies of immigrant women than among US-born women who belong to the same ethnic groups. Children of immigrant families now number one in five of all American youths - and their number has been growing seven times faster than their counterparts in the past decade. A future unhealthy generation could spell trouble for a health care sector that is already in a crisis of rising costs and inadequate insurance coverage. All in all, it seems the longer one lives in the US, the greater the risk to one's health. That can hardly be welcome news for the richest and freest nation on Earth.