	Introduction

Virtually every federal crime comes with a hidden feature. The result is the work of 18 U.S.C. 2, which visits the same consequences on anyone who orders the commission of a federal crime. Section 2(a), the aiding and abetting subsection, is more frequently prosecuted than §2(b), the causes subsection. Aiding and abetting means assisting in the commission of someone else's crime. Section 2(a) demands that the defendant embrace the crime of another and consciously do something to contribute to its success. A completed offense is a prerequisite to conviction for aiding and abetting, but the hands-on offender need be neither named nor convicted. It happens most often when there is a substantial culpability gap between the accomplice or co-conspirator and the primary offender. Section 2(b) applies to defendants who work through either witting or unwitting intermediaries, through the guilty or the innocent. Whether the intermediary is a subordinate or an undercover government agent, he may be well aware that his conduct constitutes an element of the underlying offense. On the other hand, whether the intermediary is a dupe or a facilitating governmental official, §2(b) also applies even if he is unaware of the nature of his conduct. When the intermediary is an innocent party, no one but the "causing" individual need commit the underlying offense. Withdrawal Defense

Federal courts sometimes mention a withdrawal defense comparable to one available in conspiracy cases. Aiding and abetting needs a completed offense. Proponents of a general withdrawal defense may claim support from recent dicta in Rosemond . 841) and discharging a firearm during a drug trafficking offense (18 U.S.C. The Supreme Court explained that an accomplice must know of the substantive offense beforehand in order to be shown to have embraced its commission. It did so in a manner suggesting an accomplice might be able to withdraw and escape liability prior to the commission of the substantive offense, even if he had contributed to the crime's ultimate success. Civil Liability

"Congress has not enacted a general civil aiding and abetting statute....
Virtually every federal criminal statute has a hidden feature; primary offenders and even their most casual accomplices face equal punishment. This results from 18 U.S.C. 2, which visits the same consequences on anyone who orders or assists in the commission of a federal crime.
Aiding and abetting means assisting in the commission of someone else's crime. Section 2(a) demands that the defendant embrace the crime of another and consciously do something to contribute to its success. An accomplice must know the offense is afoot if he is to intentionally contribute to its success. While a completed offense is a prerequisite to conviction for aiding and abetting, the hands-on offender need be neither named nor convicted.
On occasion, an accomplice will escape liability, either by judicial construction or administrative grace. This happens most often when there is a perceived culpability gap between accomplice and primary offender. Such accomplices are usually victims, customers, or subordinates of a primary offender.
Section 2(b) (willfully causing a crime) applies to defendants who work through either witting or unwitting intermediaries, through the guilty or the innocent. Whether the intermediary is a subordinate or an undercover government agent, he may be well aware that his conduct constitutes an element of the underlying offense. On the other hand, whether the intermediary is a dupe or a facilitating governmental official, §2(b) applies even if the intermediary is unaware of the nature of his conduct. Section 2(a) requires two guilty parties, a primary offender and an accomplice. Section 2(b) permits prosecution when there is only one guilty party, a "causing" individual and an innocent agent. Both subsections, however, require a completed offense.
Federal courts sometimes mention, but rarely apply, a withdrawal defense comparable to one available in conspiracy cases. Proponents of a general withdrawal defense in §2 cases may find support in recent Supreme Court dicta. In Rosemond, the Court explained that an accomplice must know of the pending substantive offense in order to be shown to have embraced its commission. It did so in a manner suggesting that an accomplice might be able to withdraw and escape liability prior to the commission of the substantive offense, even if he had contributed to the crime's ultimate success.
There is no general civil aiding and abetting statute. Aiding and abetting a violation of a federal criminal law does not trigger civil liability unless Congress has said so in so many words.
This report is an abridged version of CRS Report R43769, Aiding, Abetting, and the Like: An Overview of 18 U.S.C. 2, by [author name scrubbed], without the footnotes, attribution for quotations, and citations to authority found there.