The case of the wrongfully jailed teenager appears to be moving towards an acceptable conclusion. Lin Qiaoying, the 17-year-old who served about two months of a four-month sentence in Tai Tam prison after confessing for some reason that her entirely valid passport was a fake, has long since returned to her family in New Jersey. Other examples of high-handed treatment by Immigration Department officials have since surfaced and the police have conducted an extensive investigation of the subject. As a result, this newspaper reports today, the Government's Ombudsman will conduct a further study, probably leading to new Immigration Department guidelines. This should mean fewer such future cases, in which professional standards of interviewing suspects and collecting evidence are bypassed. On the surface, the Lin Qiaoying case is an egregious example of bureaucratic arrogance. Singled out for special scrutiny, the teenage girl confessed to a crime she had not committed and was bundled off to prison. No effort was made to test the authenticity of her travel document, which was valid despite a minor discrepancy of fact. However, as we noted previously, this case does have its complications. Immigration officials believe there is growing use of false documents; last year alone they investigated 3,500 cases and prosecuted 1,500. They therefore pay special attention to certain travellers. They felt they had reason to look closely at Miss Lin's papers. Her mother in America has reported losing five green cards - the official document that permits residence in the US - in five years and twice in that time has reported theft of all the family's travel documents. Three different people used the passport of a sister to travel from China to the US, via Hong Kong, in 1998, and two others used the passport of a brother. None of this excuses some of methods used; Ms Lin was denied basic protection and jailed without a test of the evidence. Other examples of wrongful treatment also indicate there are serious problems within the department. Thus the just-completed police report, and the Ombudsman's study to come, are therefore welcome. They give reason to hope there will be far fewer such examples in the future, while still allowing immigration officers to perform their important duties.