A lawyer representing a child pornography suspect in Washington state has told the federal judge overseeing the case that government prosecutors should essentially put up or shut up.

In a new Monday filing, Colin Fieman forcefully argued that the government must provide him and his client, Jay Michaud, access to the source code of the FBI’s "network investigative technique" (NIT). In this case, United States v. Michaud, the government has refused to do so, despite the fact that it did so in a related case in Nebraska, United States v. Cottom.

Fieman continued, saying that the court should note that the "actual NIT discovery is not classified, a fact that is otherwise hard to reconcile with the harms the Government claims might arise from its disclosure," and that the court could "fashion a protective order" that would prevent public disclosure of the NIT. If his efforts are successful, it would mark yet another ruling in favor of defendants in another one of the 135 "Operation Pacifier" child pornography cases that are being prosecuted nationwide.

As the Tacoma-based federal public defender wrote:

The problem for the Government is that, even if all of that were true, the situation in this case would remain the same: a choice between deferring to the Government’s position that it will not or cannot comply with the Court’s discovery order and upholding Mr. Michaud’s constitutional rights to effective representation and a fair trial. As detailed in the accompanying declarations, the discovery ordered by the Court goes to the heart of Mr. Michaud’s defense. The Supreme Court has already made plain that, in situations like this, a defendant’s constitutional rights must prevail. As a result, nothing in the Government’s proposed pleading about potential harms can alter the ultimate choice it must make between disclosure and dismissal. Jencks v. United States, 353 U.S. 657, 672 (1957) ("the criminal action must be dismissed when the Government, on the ground of privilege, elects not to comply with an order to produce[.]").

Since Fieman filed his third motion to compel discovery in January 2016, there have been two other judges in two related cases in different states that have ruled to suppress evidence found as a result of the NIT. Those cases, in Oklahoma and Massachusetts, have been significantly hindered unless those rulings are overturned on appeal. (Earlier this month, a defense attorney in West Virginia filed a new motion to withdraw a guilty plea based on these other rulings.) These cases are a small handful in a group of 135 that have so far been prosecuted.

As Ars has reported before, in early 2015, investigators used this NIT malware to penetrate the digital security of Tor users accused of accessing the Tor-hidden child pornography site called "Playpen." In yet another related case prosecuted out of New York, an FBI search warrant affidavit described both the types of child pornography available to Playpen’s 150,000 members and the malware’s capabilities.

As a way to ensnare users, the FBI took control of Playpen and ran it for 13 days before shutting it down. During that period, with many users’ Tor-enabled digital shields down—revealing their true IP addresses—the government was able to identify and arrest the 135 child porn suspects. (However, nearly 10 times that number of IP addresses were revealed as a result of the NIT’s deployment, which could suggest that still more charges could be filed.)

The judge is set to hear arguments between Michaud’s lawyers and prosecutors in a hearing in federal court in Tacoma, Washington, on Thursday morning.

"The defendant also contends that the government’s disclosure of information pertaining to a different network investigative technique in another case is relevant to the inquiry in this case. It is not," Peter Carr, a Department of Justice spokesman told Ars by e-mail. "The Cottom case in the District of Nebraska, No. 13-cr-108, involves a different investigation, of a different website, using a different investigative technique than the one pertinent to the defendant’s case."