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Using Cooperation to Avoid Trial in Multi-Defendant Cases
The Cooperator’s Calculation
Someone in every multi-defendant federal case cooperates first. The question that governs the remaining defendants’ exposure is not whether cooperation will occur but when, and whether the person cooperating possesses information sufficient to foreclose the others’ options at trial.
In 2019, in a wire fraud prosecution in the Eastern District involving seven defendants and a joint defense agreement that lasted four months, the first cooperator came forward before the government had completed its document review. The remaining defendants learned of the defection when the cooperator’s name appeared on a supplemental witness list. The joint defense agreement, which had governed the exchange of privileged strategy for the better part of a season, became irrelevant in the span of a single filing.
The prisoner’s dilemma operates differently in federal practice than in the theoretical model. Defendants in a multi-defendant case are not separated. They communicate through counsel, through joint defense agreements, through the quiet conferences that occur in hallways outside courtrooms. The information is present. The trust is not. Silence demands faith that every co-defendant values solidarity over self-preservation, and the government’s sentencing structure is designed, with considerable precision, to ensure that faith does not hold.
The defendant who cooperates first receives the most favorable terms, and the government ensures that every defendant knows it.
The Proffer Session and Its Consequences
Before cooperation begins, there is the proffer.
The proffer session, sometimes called a “Queen for a Day,” is the meeting at which a defendant and counsel sit across a table from federal agents and prosecutors and disclose what the defendant knows about the conduct at issue, the roles of co-defendants, and the evidence that exists. The defendant signs a proffer agreement before the session commences, a document that restricts the government’s ability to use the defendant’s own statements against them at trial, though with exceptions that consume much of the protection.
The exceptions are not abstract. If the defendant provides false information during the proffer, or later testifies in a manner inconsistent with what was said in that room, the agreement dissolves. Everything disclosed becomes available to the government. A proffer is, in this respect, an act of irreversible exposure: the defendant cannot unsay what has been said, and the protections that made the disclosure possible are conditional on a standard of truthfulness that the government, not the defendant, evaluates.
Most defendants who enter a proffer room have already decided to cooperate. The meeting is presented as exploratory, but in practice it functions as an audition. The prosecutors are assessing the value of what the defendant can offer, the agents are comparing the defendant’s account against what they already possess, and the defendant’s attorney is attempting to present enough to demonstrate value while withholding enough to preserve a negotiating position: a calibration that is, if we are being precise, more instinct than science. The margin between disclosing too much and disclosing too little is not something any manual can locate.
What the defendant experiences in that room seldom resembles what they anticipated. The preparation with counsel, the rehearsal of the narrative, the careful framing of the defendant’s role as peripheral rather than central: all of it encounters the blunt questions of agents who have already reviewed the wiretaps, the financial records, the co-defendant’s prior proffer. The defendant discovers, often for the first time, how much the government already knows. Whether the resulting disclosure constitutes “substantial assistance” is a determination that will not be made in that room, or that week, or in some cases that year.
The defendant goes home and nothing happens for a while.
Substantial Assistance Under Section 5K1.1
The mechanism by which cooperation translates into a reduced sentence is Section 5K1.1 of the United States Sentencing Guidelines. The section permits a court to impose a sentence below the guideline range if the government files a motion stating that the defendant provided substantial assistance in the investigation or prosecution of another person. The motion is filed by the government, and only the government can file it. The defendant and defense counsel possess no authority to invoke Section 5K1.1 independently, regardless of the quality or extent of the cooperation provided.
A cooperation agreement is not a contract in the way most defendants understand contracts. It is a document in which one party retains all the discretion and the other party assumes all the risk.
The distinction between “substantial” and “non-substantial” assistance is not defined with precision in the Guidelines. The commentary lists factors a court should consider: the significance and usefulness of the assistance, the truthfulness of the information, the nature and extent of what was provided, the danger to the defendant resulting from cooperation, and the timeliness of the assistance. These factors guide the court’s analysis after the motion is filed, but they do not govern the prosecutor’s decision to file the motion in the first instance. That decision remains, as the Supreme Court confirmed in Wade v. United States, a matter of prosecutorial discretion reviewable only for unconstitutional motive.
In practice, this means a defendant can do everything asked of them and receive nothing in return. I am less certain about the frequency of this outcome than the preceding sentences might suggest, because the data on cooperation outcomes is not collected in a form that permits rigorous analysis, particularly across districts. What can be said is that the gap between the cooperation a defendant provides and the credit the government extends for that cooperation is not always proportional, and the defendant possesses no procedural mechanism to close it.
Section 5K1.1, standing alone, permits departure below the guideline range. It does not permit departure below a statutory mandatory minimum. For that, the government must file a separate motion under 18 U.S.C. § 3553(e). In most cases where the government files a 5K1.1 motion, the § 3553(e) motion follows. In some cases it does not. The word “may” in the cooperation agreement (the government “may” file a motion) does the work that the word “will” would undo. Counsel who do not attend to the distinction between those two words have failed the client before the proffer session begins.
There is a related provision. Federal Rule of Criminal Procedure 35(b) permits the government to move for a sentence reduction after a sentence has been imposed, based on substantial assistance the defendant provided after sentencing or the results of pre-sentencing cooperation that materialized only later. This mechanism is less common and more dependent on prosecutorial goodwill. The existence of Rule 35(b) is sometimes raised during cooperation negotiations as a form of assurance that the defendant’s assistance will eventually receive credit. In the cases where we have tracked the outcome (which is, admittedly, a limited sample drawn from our own practice and the reported decisions we monitor), the reassurance has proved warranted less often than the defendant was led to expect.
The five factors the court considers in determining the extent of a sentence reduction do not prescribe a formula. There is no conversion table that translates testimony at a co-defendant’s trial into a specific number of months. The permitted reduction is within the court’s discretion once the government’s motion is filed, and the Guidelines application notes instruct the court to give substantial weight to the government’s evaluation. The practical result is that the prosecutor determines access and the court determines extent.
Joint Defense Agreements and Their Limits
Whether a joint defense agreement survives the first cooperation overture is a question of structure, not sentiment. The agreement itself, a document establishing the common interest privilege among co-defendants’ counsel, permits the sharing of strategy, work product, and privileged communications. It does not create loyalty. It creates a framework within which loyalty can operate for as long as the interests of the parties remain aligned.
In United States v. Henke, Silicon Valley executives charged with conspiracy and financial fraud initially operated under a joint defense agreement. One executive began cooperating with the government. The shared strategy, developed over months of coordinated defense preparation, became a liability for the remaining defendants. The cooperator knew the defense theory. The cooperator knew the anticipated challenges to specific evidence. The cooperator knew, in a degree of detail that no outside witness could have possessed, what each defendant’s counsel intended to argue.
Whether courts will permit the cross-examination of a former JDA member using statements shared during the joint defense is a question the circuits have not resolved uniformly. Some agreements now include provisions specifying that a withdrawing member who later testifies against a co-defendant consents to cross-examination on prior statements. Whether those provisions hold depends on the court, the circumstances, and, in my observation, the degree to which the government’s case depends on the cooperator’s testimony.
A well-constructed JDA anticipates defection. It requires written notice of withdrawal. It prohibits disclosure of the agreement’s existence to the government. It specifies that each attorney’s fiduciary duty runs to their own client alone. These provisions are necessary. They are also, in the moment of actual defection, insufficient to prevent the harm that has already occurred. The damage a cooperating co-defendant inflicts is not limited to the information they share with the government. The damage begins with what the cooperator already knows about the defense.
Evaluating the Decision
The decision to cooperate is not reducible to a cost-benefit analysis, though it is often presented as one. The variables are knowable in theory and uncertain in practice: the strength of the government’s case without the defendant’s testimony, the defendant’s sentencing exposure, the value of the information the defendant possesses, the government’s interest in the targets the defendant can identify, and the personal consequences of being designated a cooperator, which extend well past the sentencing hearing.
And the analysis most defendants perform before calling an attorney is not the analysis that matters. The defendant has assessed the situation from the perspective of the charges as they understand them, which is to say the charges as explained by a co-defendant, or by a family member who has read the indictment, or by the defendant’s own reading of a document whose legal significance exceeds its apparent plain language. The first conversation with counsel is, in most instances, a correction.
We do not recommend cooperation in every multi-defendant case. The standard advice, particularly in districts where cooperation is common and the judiciary is receptive to 5K1.1 motions, is to cooperate early and cooperate fully. The reasoning is that earlier cooperators receive more favorable terms, which is generally accurate. What the reasoning omits is an evaluation of whether the defendant’s cooperation will produce the 5K1.1 motion on which the entire calculation depends. We have represented defendants whose information the government accepted, whose testimony the government used at a co-defendant’s trial, and who never received a substantial assistance motion because the government determined, after the fact, that the assistance did not rise to the threshold. The standard advice does not account for this outcome. Our approach begins with an assessment of whether the government needs the client’s cooperation, not merely whether the government will accept it. That distinction is often what separates a motion filed from a motion withheld.
The evidence against a specific defendant is sometimes weak enough to warrant trial regardless of what the co-defendants choose to do. A defendant’s information may be redundant to what the government already possesses. There are cases where cooperation would expose the defendant to a retaliatory risk that no sentence reduction can justify. The decision requires an evaluation of the government’s case, the client’s position within the alleged conduct, the likely behavior of co-defendants, and the specific prosecutor’s history with cooperation agreements in the relevant district. Something like half of that evaluation is informed judgment rather than data.
Timing and Procedural Sequence
The timing of a cooperation decision is constrained by procedural realities that narrow as the case advances. A defendant who cooperates during the investigation, before an indictment is returned, occupies a different position than one who cooperates after arraignment, after the joint defense has been established, after discovery has revealed the government’s evidence. The earlier the cooperation, the greater its value to the government, because early cooperators can assist in the investigation itself.
After indictment, the cooperation terrain shifts. The government has already assembled its case. The cooperator’s value diminishes unless the defendant can offer testimony that the government cannot obtain through documents or other witnesses. The proffer session at this stage is less an audition than a negotiation, and the defendant’s position depends on scarcity: how many of the other defendants have already offered to cooperate, and how much the government requires one more.
Rule 35(b) extends the window past sentencing, but the post-sentencing cooperator occupies the weakest position. The defendant has already been sentenced. The government has no pending case to resolve. The motion, if it arrives, arrives at the government’s convenience.
The architecture of a multi-defendant federal case is designed to produce cooperation. The incentive structure rewards it. The sentencing framework depends on it. The joint defense agreements that attempt to resist it are, by their nature, temporary. What remains, after the cooperation decisions have been made and the proffer sessions have concluded and the 5K1.1 motions have been filed or withheld, is a set of outcomes that reflect not only the merits of the underlying conduct but the sequence in which the defendants chose to act.
A consultation with counsel is where the assessment of that sequence begins. The call costs nothing and presumes nothing. What it clarifies is whether the architecture of the case permits a defense, or whether the architecture requires a different form of participation.