The state grand jury presentment that accuses imprisoned former state Sen. Robert Mellow with even further crimes and grotesquely unethical conduct is, like so many documents of its kind, seriously deficient in terms of transparency.

Mellow, former top executives of the Pennsylvania Turnpike Commission and a few related players are accused of a wide-ranging "pay-to-play" contracting scheme. Millions of dollars worth of turnpike contracts allegedly were awarded by political directive, in exchange for campaign contributions or other considerations, rather than on the technical merits of the proposals.

This cesspool exists because some state lawmakers have an incentive for it to continue rather than end - the campaign contributions, at least, that contractors understand they must make in order to be in play for multi-million contracts. Hence the presentment's assertion, not disputed by anyone, that there was a reprehensible "60/40 rule" under which 60 percent of turnpike contracts would go to vendors favored by the Senate majority caucus leaders and 40 percent would go to vendors favored by their counterparts in the minority caucus.

Yet the presentment does not identify most of the contractors who participated, nor does it identify other politicians who received campaign contributions or other ill-disguised bribes from contractors.

Attorney General Kathleen Kane said at a press conference that there was insufficient evidence to establish a quid-pro-quo between contractors and any of the politicians who received their campaign contributions, other than Mellow.

That, however, should not deter Kane from identifying the contractors who made the contributions and the politicians who received them. Even if there was no provable criminal conduct, is the public supposed to believe that those donations were made and received in the cause of good governance? It's a matter of transparency - who received what from whom? Let the donors and recipients explain it.

Even though the presentment concluded that Mellow's concealment of a raft of "gifts" from PNC Bank contributed to "a larger pattern of bid-rigging, improper influence and commercial bribery," it did not identify any individual at the bank who dealt with Mellow.

Kane says the case remains open so, perhaps, more details will emerge. She should ensure it by seeing that the grand jury issues a full report, beyond the criminal charges.

Meanwhile, lawmakers who invite lobbyists and others to grease them by maintaining a $250 window for unreportable "gifts" - dinner, anyone? - should permanently close that window.

Zero is the correct amount that lawmakers should be allowed to accept from anyone who does business with the commonwealth.