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Cooperating in Federal Money Laundering Investigations
Cooperation is the single most consequential decision a defendant will confront in a federal money laundering investigation, and it is almost always made too late. The client has retained counsel. The target letter has arrived, or the indictment has been returned. The question of whether to speak to the government presents itself not as strategy but as a crisis with a deadline. Most people who contact this firm about a money laundering matter have already passed the point where cooperation would have been easiest, though they have not yet passed the point where it is impossible.
The federal money laundering statutes occupy a peculiar position in the criminal code. They are ancillary charges, in the sense that every money laundering prosecution requires an underlying offense (a specified unlawful activity) from which the proceeds derive. They are also, in practice, among the most aggressively charged federal offenses in the country. Prosecutors attach laundering counts to fraud cases, drug cases, tax cases, and public corruption matters with a regularity that has rendered the charge less a standalone crime and more a multiplier of exposure. The window for cooperation has not closed, though it has narrowed in ways most clients do not yet perceive.
The Statutes and Their Reach
Section 1956 of Title 18 prohibits four categories of laundering: promotional, concealment, structuring, and tax evasion laundering. Its companion, Section 1957, covers monetary transactions exceeding ten thousand dollars in criminally derived property. The statutory maximum for a Section 1956 conviction is twenty years of imprisonment per count. For Section 1957, the ceiling is ten. Both carry fines that can reach five hundred thousand dollars or twice the value of the property involved in the transaction, and both authorize criminal forfeiture of any property connected to the offense.
What clients rarely appreciate until the charges are explained is the scope of the predicate offense list. Section 1956 incorporates, by reference, several hundred federal, state, and foreign crimes. A wire fraud conviction, a narcotics distribution charge, a violation of the Foreign Corrupt Practices Act: each can serve as the specified unlawful activity that transforms a financial transaction into a laundering count. The result is that money laundering functions less as a discrete crime and more as an amplifier of whatever the government has already chosen to pursue.
Conspiracy under Section 1956(h) carries the same penalties as the substantive offense, and it requires no proof of an overt act. The agreement to launder is itself the offense.
The Proffer
Before cooperation begins in any formal sense, the government extends a proffer agreement. The document, which defense attorneys sometimes call the queen for a day letter, is typically two to four pages. It provides limited use immunity: the government agrees not to introduce the defendant’s statements directly at trial. It does not provide transactional immunity. It does not guarantee a plea offer or a sentencing reduction. What it provides is a structured opportunity to speak, with boundaries that are less protective than they appear.
The proffer session takes place at the United States Attorney’s Office. The assigned prosecutor is present, along with one or more federal agents, defense counsel, and the defendant. The session is not recorded in most districts, though agents take detailed notes. The defendant is expected to disclose everything relevant to the investigation: their own conduct, the conduct of others, the location of documents, the structure of the scheme. Partial disclosure is treated as a failure to cooperate.
A defendant who walks into a proffer without having reviewed, with counsel, every document the government is likely to possess, every transaction that might surface, every co-conspirator whose name might arise, every inconsistency between what the defendant remembers and what the records reflect, is a defendant who will make mistakes. Some of those mistakes are correctable. Some of those mistakes will follow the defendant to sentencing.
In our practice, we do not agree to a proffer until we have conducted our own investigation of the client’s exposure. Prosecutors do not always accommodate the delay. But a proffer entered without that preparation is, in most of the cases we have handled, a more dangerous proceeding than no proffer at all.
Derivative Use and the Kastigar Waiver
The proffer agreement’s most consequential provision is the one defendants understand least. The government cannot use the defendant’s words directly. It can, and routinely does, use everything it learns from those words. This is derivative use, and the Supreme Court addressed its constitutional parameters in Kastigar v. United States. The standard proffer letter includes a Kastigar waiver, which permits the government to pursue investigative leads generated by the defendant’s disclosures without the burden of demonstrating, at a later hearing, that its evidence was obtained from an independent source.
In practice, the doctrine operates as follows. A defendant reveals that a particular wire transfer passed through a correspondent bank in a jurisdiction the government had not yet examined. The government cannot quote that statement at trial. It can, however, subpoena the correspondent bank’s records, discover additional transfers, identify new witnesses, and construct a case that encompasses conduct the defendant did not intend to reveal. The statement is inadmissible; the evidence it produced is not.
Prosecutors understand precisely what they are extracting from a proffer session. They listen less for admissions than for leads: names the government has not yet encountered, accounts it has not yet subpoenaed, jurisdictions it has not yet reached. Every answer the defendant provides opens an investigative avenue the government may pursue without attribution. In circuits that enforce the Kastigar waiver strictly, the defendant’s own disclosures can become the architecture of the prosecution’s case against them. In districts where judges scrutinize the government’s use of proffer information with greater care, the risk is diminished but never absent.
We tend to advise proffer participation when the government’s case is strong enough that trial presents unacceptable risk and when the defendant possesses information of genuine value concerning others in the conspiracy. Outside those conditions, the calculus shifts.
Whether the courts will continue to enforce that waiver with its current breadth, or whether the doctrine will contract as its implications become more visible, is a question the circuits have not yet settled.
The Debt That Silence Compounds
The arithmetic of cooperation is, if one sets aside the moral questions, straightforward. A defendant facing a guidelines range of ten to twelve years who provides substantial assistance to the government can, through a combination of a favorable plea agreement and a Section 5K1.1 motion, reduce that exposure to something in the range of four to six years. The reduction is not guaranteed. It is not automatic. It is contingent on the government’s assessment of the value, truthfulness, and timeliness of the defendant’s assistance. But the potential magnitude of the reduction is large enough that, for many defendants, cooperation represents the only realistic path to a sentence that permits a life afterward.
There is no second proffer.
The letter sits on the kitchen counter for a week, sometimes longer, acquiring the specific weight of something that cannot be undone by ignoring it. The client has already called two attorneys who told them things that were either too reassuring or too alarming to be useful. The business is still operating, or it is not. The accounts may already be frozen. By the time the client calls this office, they have usually made one of two errors: they have spoken to an agent without counsel, or they have refused to engage at all while the government’s interest in their cooperation diminished.
In 2019, before the wave of revised DOJ corporate enforcement policies, cooperation in money laundering cases followed a pattern that was, in retrospect, more favorable to defendants than the current environment. Prosecutors in most districts would extend proffer opportunities over a period of weeks, sometimes months. The timeline has compressed. A target letter today carries, in most offices, an implicit deadline that defense counsel must recognize even when the letter does not state it.
In six cases over the past two years, we have seen defendants lose the opportunity to cooperate because they waited until the government no longer required their testimony. The funder (who, in this instance, had restructured the same debt through three separate entities before the government identified the original source of funds) declined to negotiate a proffer at all by the time the defendant retained counsel. That case resolved at trial, with the sentence the guidelines predicted.
What we have observed, across a substantial number of these matters, is that early engagement with the government produces better outcomes than late engagement, though the definition of early is less clear than the advice implies.
We prepare differently for a proffer than most firms, because we have seen what happens when preparation is treated as a formality. The standard approach is to review the government’s discovery, prepare the client on the key topics, and enter the proffer session with a general sense of the client’s exposure. We conduct an independent factual investigation before the proffer occurs: bank records, transaction histories, communications, and wherever possible, interviews with individuals who can corroborate the client’s account. The purpose is not to construct a defense. The purpose is to identify, before the client speaks, every fact the government might use derivatively, so that the scope of the proffer can be discussed with the prosecutor in advance. That preparation is where the conversation begins, and a first consultation assumes nothing beyond the facts.
Sentencing Under Section 5K1.1
The sentencing reduction a cooperating defendant receives is governed by Section 5K1.1 of the United States Sentencing Guidelines. The provision permits the court to impose a sentence below the guidelines range when the government files a motion certifying that the defendant has provided substantial assistance in the investigation or prosecution of another person. The government has complete discretion over whether to file the motion. The defense cannot compel it. The court cannot request it. Only the government can file the motion.
The court considers five factors in determining the reduction: the significance of the assistance, the truthfulness and completeness of the information, the nature of the assistance, any danger to the defendant or the defendant’s family, and the timeliness with which the assistance was rendered.
Section 5K1.1 alone permits departure below the guidelines range but not below a statutory mandatory minimum. To pierce the mandatory minimum floor, the government must also file a motion under 18 U.S.C. Section 3553(e). In practice, prosecutors who file a 5K1.1 motion typically file the 3553(e) motion as well, though this is not universal. A defendant who receives a 5K1.1 motion but not a 3553(e) motion remains subject to the mandatory minimum, regardless of how substantial the assistance. Cooperation credit under the guidelines and the statutory floor exist in a relationship that is, for many defendants, the difference between a sentence measured in years and one measured in decades.
The average reduction under a 5K1.1 motion, according to Sentencing Commission data, falls in the range of fifty percent below the bottom of the guidelines. Some cooperators receive substantially larger reductions. Others receive modest adjustments. The motion itself is three pages, sometimes fewer.
When Cooperation Fails
Proffers do not always produce cooperation agreements. A defendant who provides information the government already possesses has cooperated in form but not in substance. A defendant who is inconsistent across sessions, or whose account is contradicted by a co-defendant’s proffer, has created a problem the government may choose to exploit rather than resolve. A defendant who reveals, during the proffer, conduct the government did not previously know about may find that the proffer has expanded rather than reduced their exposure.
In fraud and money laundering cases, the loss amount drives the guidelines calculation. A defendant who admits during a proffer to transactions totaling a higher figure than the government had charged may see their sentencing range increase, even if a cooperation agreement follows. The case was, for practical purposes, resolved during the proffer itself.
The Current Enforcement Climate
In May 2025, the Department of Justice’s Criminal Division released a revised White Collar Enforcement Plan that identified complex money laundering as a priority area. The plan directs prosecutors to focus on conduct that threatens national security, enriches foreign corrupt officials, and facilitates transnational criminal organizations. The revised Corporate Enforcement and Voluntary Self-Disclosure Policy, released in its department-wide form in March 2026, provides that companies meeting certain cooperation thresholds may receive declinations or reduced penalties.
For individual defendants, the policy signals are less specific. I am less certain about how the current enforcement posture will affect individual cooperation agreements than the preceding paragraph might suggest. The Department has stated that its first priority remains the prosecution of individuals, and cooperation in money laundering investigations continues to be evaluated under the same framework that has governed it for years: the quality of the information, the willingness to testify, and the degree to which the defendant’s assistance advances the prosecution of others.
The enforcement apparatus is intact, and the penalties for money laundering offenses remain among the most severe in the federal code.
One does not cooperate with the federal government out of goodwill. One cooperates because the alternative has been calculated, and found worse.
The decision to cooperate in a federal money laundering case is not, in the end, a legal question. It is an exercise in the measurement of risk: the risk of speaking weighed against the risk of silence, the risk of trusting the government’s representations weighed against the risk of proceeding to trial with the evidence the government has already assembled. No article can resolve that calculus for a particular defendant, because the calculus depends on facts that only the defendant and their counsel possess. What can be said is that the decision is better made with information than without it, better made early than late, and better made with counsel who have conducted these negotiations before and can describe, without exaggeration, what the process requires.