With all the Sept. 11 hijackers dead and most of their key confederates, financial backers, and bosses at large in Asia, the government has few people available to prosecute for the crimes of al-Qaida. And while it's deploying massive legal resources to convict the likes of Zacarias Moussaoui, John Walker Lindh, Jose Padilla, and others, the government may have a hard time obtaining convictions. Yes, each of these poster-children defendants may have trained with al-Qaida cells, mouthed approval of al-Qaida goals, or consorted with people who consorted with the Sept. 11 hijackers. They may even have prepared to become hijackers or terrorists themselves. But this still may not get prosecutors the kind of proof beyond a reasonable doubt necessary for a death sentence, or even a conviction for the events of Sept. 11 or other acts of terrorism. Fortunately for the government, federal conspiracy law is a vast and flexible legal instrument. While many states have narrow conspiracy laws—limiting guilt to those who participate directly in the planning or execution of specific crimes—Congress has increasingly allowed federal prosecutors to reap the benefits of guilt by association. It has done so presumably because it sees a unique and urgent federal role in stopping the kind of complexly organized and elusive criminal networks that cross state and national boundaries. Like al-Qaida, these networks are often deliberately designed to operate under the radar of conventional law and law enforcement practices, and to give their members plausible deniability that they knew who was doing what. And while federal racketeering law has long been criticized for its extraordinary sweep and breadth, it's available to federal prosecutors, who may have finally found in these terror trials a justification for using it. Indeed, they should go further, as I'll argue below. If the already broad federal conspiracy rules can't produce a conviction based on circumstantial evidence, the government should consider bringing criminal charges against terrorists under RICO—the federal racketeering statute. The indictment in the case of United States v. Zacarias Moussaoui is a good example of the low standards of proof necessary to bring a federal conspiracy case. This is a wonderful document, artfully drafted to tell a terrifying story of the rise and scope of al-Qaida and to implicate Moussaoui in al-Qaida's most heinous acts. But on inspection the indictment is almost all al-Qaida and hardly any Moussaoui. Most of the narrative is laid out in the obligatory list of "overt acts." In conspiracy law, the core criminal act is simply the defendant's "act" of somehow agreeing to a particular illegal goal. These overt acts don't have to be crimes, or even attempted crimes, by themselves. It is sufficient to enumerate mundane actions taken by the defendant or any alleged co-conspirator that are consistent with the illegal goal. In the Moussaoui indictment, the grand jury (presumably following the script provided by the U.S. attorneys) enumerated 112 "overt acts," and these are, taken as a whole, heinous indeed. But that is because most of them depict the actual hijackings or steps taken by Osama Bin Laden or his aides in financing and planning them. Only 17 of these acts are attributed to Moussaoui at all. But in the indictment these are interspersed in the list of 112, so the enumeration reads almost like the script of a film, where the relentless movement of the main actors toward the hijacking is juxtaposed by a photo montage with more equivocal things done by Moussaoui. This artful montage splicing builds his actions into an impression of inexorably converging forces. These 17 acts by Moussaoui run quite a gamut, from being present at an al-Qaida training camp, signing up for flight training in Oklahoma, and flying around the world with a lot of cash to possessing knives, binoculars, and shin guards. They also include, somewhat oddly, his joining a gym in Oklahoma and—somewhat tautologically—falsely telling agents that he was simply interested in learning to fly. The closest thing to a direct link between Moussaoui and the events of Sept. 11 is overt act No. 67, where one Ramzi Binalshibh, a non-hijacker with undeniably close financial ties to the actual hijackers, sent $14,000 in money orders from Germany to Moussaoui in Oklahoma. Maybe this transfer was somehow a causal step toward the crashes. Or maybe it was related to another plan. Some steps sound like part of a plan to become a hijacker. But most of the steps are ambiguous, and all are pretty circumstantial. Under existing federal conspiracy law, however, these steps may suffice: Even if not one of these acts was a crime or even an attempted crime, so long as Moussaoui in some way manifested agreement with the crimes of Sept. 11—somehow communicated to the hijackers or those involved in the planning that he assented to the action and in some general sense was willing to lend aid—the conspiracy charge may be sufficient. The jury needs only to find in Moussaoui's conduct a "speech act" that said to the hijackers, "Great plan, and I'm there for you." Then, through the leveraging magic of federal conspiracy law, he can be convicted of the crimes of Sept. 11 themselves. The government will thus implore the jury to "connect the dots," sometimes literally by drawing pictures of chains and rings and wheels to describe how the structure of the network of command and coordination worked. But even if the jury can convict here, the question is whether it will. Jurors and even trial judges sometimes balk at the amazing reach of federal conspiracy law and worry about how all sorts of Mr. Littles can get ensnared in the faraway crimes of the Mr. Bigs. And in a case like this, even if they are willing to convict, will they be willing to impose death? Remember, the jury that convicted Terry Nichols as a full conspirator in the Oklahoma City mass murder still refused to sentence him to death, even though the law made the death sentence impeccably logical. Moreover, what if the jurors cannot "connect the dots" between the Sept. 11 hijackers and Moussaoui himself? What if he was involved in another plot altogether? Luckily, the government has had another device available all along that might solve this problem: the famous, or infamous, Racketeer Influenced and Corrupt Organizations Act of 1970—the unfortunately nicknamed RICO law. Using RICO, prosecutors could handily present the jury with a package of dots pre-connected by congressional mandate. Because under RICO, it may not matter whether Moussaoui helped plan crimes, so long as he lent moral support to an o rganization. RICO was first conceived as a tool to prosecute organized crime, most obviously the Mafia. And its key component lay in assuming the existence of an "enterprise" that crooks manipulated for illegal ends. In the original conception of RICO, this enterprise was a legitimate organization—usually a corporation or labor union—and the crooks committed a RICO violation by laundering criminal profits through or investing them in the enterprise, or by using the otherwise good offices of the enterprise to commit illegal acts. The "act" of racketeering thus simply consists of an individual committing at least two "predicate acts" within 10 years in a manner somehow tied to the enterprise, and those predicate acts can be just about any act constituting a crime under state or federal law. After the first fertile decade of RICO prosecutions, the Supreme Court faced a paradox. In a 1981 case, United States v. Turkette, a bunch of gangsters defended against a RICO charge by denying that they had ever had any contact with or engaged in any legitimate business activity at all—they were, they argued, nothing but crooks and hence, immune to a RICO charge. This Catch-22 was too much for the Supreme Court, which held that RICO could apply even here. As a result, any criminal combine that exhibits any sort of unity of action—i.e., that meets some Aristotelian criteria of aesthetic coherence—can now be deemed a RICO enterprise. Moreover, the enterprise need not have a pecuniary goal—a shared ideology is fine, so long as the racketeering activity meets the trivially easy test of affecting interstate commerce. The government can now map the concept of an enterprise onto almost any kind of criminal organization, call it a RICO enterprise, then prosecute anyone working for that enterprise of a RICO violation. It would not be difficult to rejigger the Moussaoui case as a RICO prosecution. Al-Qaida is an "enterprise" by any fair reading of the precedents. It has what courts call an "ascertainable structure" and a clear organizing purpose. And the dead or distant hijackers and planners themselves committed RICO predicate acts. If Moussaoui can be shown to have committed two crimes himself—to help further al-Qaida's goals, or by appropriating any of al-Qaida's resources, he could be guilty of a "substantive" RICO count. That's obviously a problem if not one of the steps taken by Moussaoui was itself a crime. But RICO's infinite magic goes further. Even though RICO itself looks like a conspiracy law, there's a separate crime of conspiring to violate RICO. Call it double-counting or legalistic mysticism, but so long as Moussaoui in some way "adopt[s] the goal of furthering or facilitating the criminal endeavor" (to quote the Supreme Court in Salinas v. United States), he is guilty of conspiring with someone else's RICO violation and—through those always available leveraging rules—he can be guilty of every crime committed by any co-conspirator committed to furthering the goals of al-Qaida. And, with a bit more leveraging, the death-penalty-eligible acts of the (now dead) hijackers can be imputed all the way back to Moussaoui. So why hasn't the government used RICO in the terror trials? Perhaps prosecutors thought merely invoking the mobster/racketeer imagery of RICO would have trivialized the crimes of Sept. 11. Perhaps they feared that the transparent utility of RICO in easing their case might backfire, might cause the jurors to spit in the face of Congress for making things too easy for the government. But calling al-Qaida a RICO enterprise would add color to an already dramatic case and it might just help the government sprinkle the magical federal conspiracy dust on an even wider group of characters. Congress has supplied a special instrument to combat large, conspiratorial organizations; the government should try to sell it to jurors. At the very least it would be preferable to indefinite detentions or secret tribunals.