The huge corruption scandal exposed Wednesday morning that led to the arrest of some 30 suspects is the result of intense investigative work that has been going on for more than a year. The list of suspects includes Deputy Interior Minister Faina Kirshenbaum, former Tourism Minister Stas Misezhnikov, the director general of a government ministry, heads of local authorities and other senior officials.

The list leaves no room for doubt – the suspicions involve a well-oiled system of bribery centered around a single political party, Yisrael Beiteinu, a party now tainted with the stain of corruption. Yisrael Beiteinu denied the claims and accused law enforcement of political persecution. While this might be a new case, there’s nothing really new about that.

This investigation was born of many pieces of information, complaints, reports and intelligence that was accumulated by the Israel Police until finally the penny dropped. Detectives in the Lahav 433 investigation unit were able to piece together the puzzle until it formed a picture of a nationwide bribery operation. According to the reports, the suspicions involve bribery and breach of trust to the tune of millions of shekels – all public funds – that were allegedly diverted for irrelevant reasons by decision-makers influenced by bribes.

The primary allegations are that the politicians and senior officials took cuts of what they arranged to have allocated to various groups and nonprofit associations from the public purse. These senior officials also allegedly received money in return for arranging appointments and jobs for their cronies. The “protectzia” method of providing for associates was upgraded to protectzia for payment.

Ministers, deputy ministers, MKs and Knesset committee chairmen all have influence on setting criteria for government support of various organizations. It isn’t so hard to tailor these criteria so that they look objective but actually match the characteristics of a specific group that the political official favors – for ideological reasons or because he’s been encouraged to favor it by a bribe. One assumes that the politicians will claim that these funds were already earmarked for these purposes and that there were no improper diversions; they will also try to present a legal front for receiving any monies they may have received, or a legal justification for the jobs that went to their friends.

From the minute the pieces of information began to form a single mosaic, Attorney General Yehuda Weinstein became the most important force in advancing the investigation. In such an investigation there is no alternative to close supervision by the attorney general and the state prosecution, because it requires approval for the use of especially sensitive investigation methods against very high-level officials.

This type of probe requires, for example, wiretapping MKs and ministers and searching the offices of politicians and political parties. Moreover, such an investigation requires an understanding of the whole power balance in the coalition – how monies are transferred, how budgets are allocated, who approves them, and how and why certain coalition decisions are made on the background of conversations and agreements made between the suspects behind the scenes.

Such an investigation must also have been compartmentalized within the prosecutors’ office and the Justice Ministry, since it involved government ministries and senior officials in the civil service who interact almost daily with the legal system and senior attorneys in the Attorney General’s Office and the State Prosecutor’s Office. One cannot risk having a senior Justice Ministry official sitting with a ministry director general being investigated accidently revealing something about the probe to one of its targets. This makes it highly likely that this investigation was personally supervised by Weinstein and State Prosecutor Shai Nitzan.

The prosecution office that deals with these kinds of cases is the economic department of the State Prosecutor’s Office, headed by attorney Dan Eldad. It was this department that, for example, led the investigation into the Israel Tax Authority corruption scandal that erupted in 2007 and was at the time thought to be the most serious corruption case ever involving the civil service because of the possibility that the country’s whole tax-collection system had been compromised. This case is no less serious, since it alleges the undermining of the funding mechanisms for nonprofit associations and local authorities, and the method of making appointments at the municipal and national level.

The decision to arrest the targets on Wednesday morning and make the covert investigation public was almost certainly made by Weinstein, especially given the sensitive timing, in the midst of an election campaign.

Why did he choose to go public with it now? Somehow, it always happens this way. The most sensitive and influential investigations seem to always go public when there are elections, when it is the most uncomfortable, when it looks most like the settling of political scores, when it looks like the legal system is serving the interests of the right, the left, the center, that presidential candidate or the other prime ministerial contender, or some other political objective.

During the race for state president this phenomenon was clearly evident, but it also demonstrated that the legal system conducted itself without political prejudice. During the presidential campaign there were allegations investigated that led to both Silvan Shalom of Likud and Benjamin Ben-Eliezer of Labor dropping out of the race. The latter became a suspect in a graft probe in which a decision on how to proceed has yet to be made, primarily because of Ben-Eliezer’s precarious health.

This new corruption case was of so large a scope that it required the questioning of a large group of suspects simultaneously. One can bet that the decision to go public with the case at this time was the result of a sufficient accumulation of incriminating evidence combined with the need to arrest all the suspects at the same time so that they would not be able to coordinate their testimonies. We know from listening to the recordings of Ehud Olmert and Shula Zaken that smart suspects in political positions know how to weave stories that will acquit them when they need to.

This investigation will, of course, accompany the election campaign in the coming weeks. From a political perspective, however, it isn’t clear that the probe will cause serious damage to the party at the center of it. On the contrary; past experience shows politicians at the center of corruption scandals manage to exploit the investigations to sling mud at the investigators, the attorney general and the prosecution, claim political persecution and thus get the votes of their admirers.