18 U.S.C. 371 makes it a separate federal crime or offense for anyone to conspire or agree with someone else to do something which would amount to another federal crime or offense. Under this law, a conspiracy is an agreement or a kind of partnership in criminal purposes in which each member becomes the agent or partner of every other member.

How the Government Establishes a Conspiracy Offense

To establish a conspiracy offense, it is not necessary for the government to prove that all of the people named in the indictment were members of the scheme, that they had entered into any formal type of agreement, or that they had planned together all the details of the scheme to commit the intended crime.

Also, because the essence of a conspiracy offense is the making of the agreement itself (followed by the commission of any overt act), it is not necessary for the government to prove that the conspirators actually succeeded in accomplishing their unlawful plan.

What the evidence in the case must show beyond a reasonable doubt is:

  • First: That two or more persons, in some way or manner, came to a mutual understanding to try to accomplish a common and unlawful plan, as charged in the indictment.
  • Second: That the person willfully became a member of such conspiracy.
  • Third: That one of the conspirators during the existence of the conspiracy knowingly committed at least one of the methods (or overt acts) described in the indictment.
  • Fourth: That such overt act was knowingly committed at or about the time alleged in an effort to carry out or accomplish some object of the conspiracy.

What Is an Overt Act?

An overt act is any transaction or event, even one which may be entirely innocent when considered alone, but which is knowingly committed by a conspirator in an effort to accomplish some object of the conspiracy.

How Someone Becomes a Conspirator

A person may become a member of a conspiracy without knowing all of the details of the unlawful scheme or knowing who all of the other members are. If a person has an understanding of the unlawful nature of a plan and knowingly and willfully joins in that plan on one occasion, that is sufficient to convict him for conspiracy even though he did not participate before or only played only a minor part.

Of course, mere presence at the scene of a transaction or event, or the mere fact that certain persons may have associated with each other, and may have assembled together and discussed common aims and interests, does not necessarily establish proof of a conspiracy. Also, a person who has no knowledge of a conspiracy, but who happens to act in a way which advances some purpose of one, does not thereby become a conspirator.

Differing Definitions of Conspiracy

Formerly, this offense was much more circumscribed in its meaning than it is now. Lord Coke describes it as "a consultation or agreement between two or more to appeal or indict an innocent person falsely and maliciously, whom accordingly they cause to be indicted or appealed and afterward the party is acquitted by the verdict of twelve men."

The crime of conspiracy, according to its modern interpretation, mostly involves conspiracies against the public, such as endangering the public health, violating public morals, insulting public justice, destroying the public peace, or affecting public trade or business.

What Is the Punishment for Conspiracy?

To remedy these evils, the guilty persons may be indicted in the name of the commonwealth. Conspiracies against individuals have a tendency to injure them in their persons, reputation, or property. The remedy in these cases is either by indictment or by a civil action.

By the former laws of the United States, a willful and corrupt conspiracy to cast away, burn, or otherwise destroy any ship or vessel with intent to injure any underwriter thereon, or the goods on board thereof, or any lender of money on such vessel, is made felony, and the offender punishable by fine not exceeding $10,000 and by imprisonment and confinement at hard labor not exceeding 10 years.

By the old Revised Statutes of New York, any two or more persons shall be guilty of a misdemeanor if they conspire to:

  1. Commit any offense.
  2. Falsely and maliciously to indict another for any offense
  3. Falsely move or maintain any suit.
  4. Cheat and defraud any person of any property, by any means which are in themselves criminal.
  5. Cheat and defraud any person of any property, by means which, if executed, would amount to a cheat, or to obtaining property by false pretenses.
  6. Commit any act injurious to the public health, to public morals, or to trade and commerce, or for the perversion or obstruction of justice, or the due administration of the laws.

No other conspiracies are there punishable criminally. And no agreement, except to commit a felony upon the person of another, or to commit arson or burglary, shall be deemed a conspiracy, unless some act besides such agreement be done to effect the object thereof, by one or more of the parties to such agreement.

When a felony has been committed in pursuance of a conspiracy, the latter, which is only a misdemeanor, is merged in the former; but when a misdemeanor only has been committed in pursuance of such conspiracy, the two crimes being of equal degree, there can be no legal technical merger.