The police arrested the officials, as well as their head Atsuko Muraki, director general in the welfare ministry, last summer. Prosecutors and police claimed she was behind issuing the fake postal certificate. Testimony from her arrested subordinates supported this. So, high-level administrator abuses power to line own pockets. A nice and juicy story, and with political implications too. Of course, as MTC pointed out at the time, you do not arrest a high-ranking official unless you're really sure of your case. If you're wrong, the backlash would be absolutely fierce.
You know what's coming next, don't you: The case against Muraki came up in court, and in court the junior officials retracted their testimony. They denied that their boss had been involved in any way. During the interrogations (which, in Japan, is often not recorded and without a lawyer1) they first claimed she'd had nothing to do with it, but the prosecutors lied to them, saying the others had fingered her, and that unless their testimony agreed they'd get a much harsher sentence than the others. This kind of pressure is, needless to say, not legal. When this came to light the judge immediately discarded all suspicious testimony as evidence. Without it the case fell apart, and she was found innocent of any charges last month.
But wait - it gets better! Her acquittal not only made the Osaka Special Prosecutor unit look bad, it kicked up exactly the kind of anthill that MTC predicted last year. And amid the scurrying, one defence lawyer took a second look at a certain floppy disk with the certificate that the prosecutors had seized. This eagle-eyed lawyer realized that the date of last change of that file had been altered by the prosecutors. The date on the disk seemed to corroborate the prosecutors claims, but the original date (which had been noted in the initial documents) contradicted it; and the original date was in fact evidence of her innocence.
At this point, the excrement hit the fan. Pachyderm-scale excrement and an industrial fan, with lots of spreading power. Star prosecutor Tsunehiko Maeda admitted he had changed the date on the disk but claimed he'd done it by mistake. Later on - as the investigation proceeded - he admitted he'd done it deliberately, both to destroy unfavourable evidence that she was innocent and to create a better case for her guilt.
So, a prosecutor deliberately destroyed evidence of the accuseds innocence and faked evidence against. He even talks about this with his colleagues at one point, and four of them go to their bosses, unit chief Otsubo and his deputy Saga, in February and tell them about Maedas fake evidence. Appalled, Otsubo and Saga immediately order an internal investigation to get to the bottom of it -
Hahaha!! This is the Osaka prosecutors office - of course they didn't! What Otsubo and Saga did was order the four prosecutors to keep their mouths shut, and ordered Maeda to make up a good excuse and write an internal report, in case the tampering came to light. He had to rewrite the report a number of times, in fact, until Otsubo was satisfied the excuse was good enough. Cover up the whole thing in other words, and continue with the case pretending the evidence tampering hadn't happened and ignoring that their main suspect was innocent.
So here we have not just one rogue prosecutor, but seven, in a special investigative unit - supposedly the best of the best, handling the difficult, sensitive cases - all covering up illegal tampering with evidence. All knowing the testimonies are untrue. All of them realizing their suspect is in fact innocent, but still dead set on bringing her to trial and send her to prison for a crime she never did. All of them believing that their own careers and saving face of the Osaka prosecutor's office is worth imprisoning and destroying the life of an innocent person.
Would you believe that this is a single, isolated incident? No, me neither. And defendants in earlier cases with the same unit are already showing up, claiming they got railroaded in the same way, with witnesses pressured to change their stories to fit the prosecutors case. This piece of morbid entertainment may well go on all through next year or longer.
And neither should you expect this to be limited to Osaka. Prosecutors have a rotating system where they change workplace every few years, and the same people - and the same corrupt culture - moves between Osaka, Tokyo and the other large cities (rural districts aren't good enough for these people so the culture may well be different there). If there are no recent cases of prosecutors altering testimony and covering up evidence in Tokyo then it's probably because nobody has looked for it.
A final question is why they arrested her in the first case. It seems they never had any evidence on her, but went on a fishing expedition that came up empty. They had real suspects already, that really are guilty of the crime. They didn't need another suspect to solve the case. Again, you don't arrest people with power, money and friends in high places unless you're pretty sure of yourself; and yet, they did2.
My completely unfounded guess is that it's election related. Remember, at the time it seemed there was a connection to Muraki and to a DPJ diet member - an opposition party member - and this fraud was uncovered just as the national election campaign was heating up. An embattled LPD could really have used a juicy scandal to hang on the opposition. My guess is that some LDP member leaned on the prosecutors office - called in a few favours perhaps - to be aggressive and move very fast with this case, so that any connection to that DPJ member would be uncovered before the election. As it turned out there was no connection to find, the LDP lost the election, and the prosecutors found themselves stuck with an innocent high-level administrator they never should have arrested in the first place.
This is a disaster for the already tarnished image of the Japanese judicial system. It's worth noting that the witness tampering didn't really raise many eyebrows; that kind of misbehavior is pretty much expected already. People are already wary of reporting things or coming forward as witnesses on the fear of becoming accused of something. But the falsified evidence brings it to a different level. A trustworthy legal system - like reliable social security, defence, disaster management and medical systems - is fundamental for a stable society, and if it frays badly then everybody loses out.
#1 The heavy reliance on testimony and confessions over other forms of evidence seems to be a serious weakness of the Japanese judicial system, when you consider just how unreliable and malleable our memories are. Given enough time and pressure - and prosecutors have plenty, with suspects in jail for months at a time - you can make people believe they saw or did almost anything. This is nothing new; the conviction rate of over 99% is, let's say, improbable at best, and the unreliability of testimony is probably a major cause of that. There's a drive for mandatory recording of all interrogations in order to detect undue pressure and attempts to change statements to fit the case. The police and prosecutors are dead set against such recordings, presumably for the very same reason.
#2 Equality in the eyes of the law is an important principle and an admirable ideal. The reality - in Japan and everywhere else - is of course that we're not equal. A homeless, barely literate day labourer will not have the same treatment by the law as a high-level government official. Money buys you better lawyers and resources to do your own investigations; your web of contacts gives you access to all kinds of other resources and information (references to high-powered lawyers and other professionals for instance); and your education and professional life gives you knowledge of your rights, of the resources you can draw on, and - importantly - the social confidence to make use of all of this in the face of scolding officials. And officials, knowing all this, will be much gentler and more careful when the suspect is from the top of society rather than the bottom.