The Boston Marathon bombing suspects, brothers Dzhokhar and Tamleran Tsarnaev, have been called both "accomplices" and "conspirators" in news reports.
But legally speaking, what do these terms actually mean?
Here are the legal differences between conspiracy, accomplice liability, and another criminal term you may be hearing with regard to the Boston bombings: being an accessory to a crime.
What Is a Conspiracy?
Criminal law defines conspiracy as two parties who knowingly agree to commit a criminal act. Each member of the conspiracy is called a co-conspirator.
The federal conspiracy statutes require each co-conspirator to commit some sort of action that furthers the goal of the conspiracy.
Massachusetts law, however, does not require a co-conspirator to actually take any action in helping the other conspirators commit the crime; an agreement to do something unlawful is enough. This makes Massachusetts law much broader.
What Is an Accomplice?
An individual who commits a crime is also called the principal. Generally, a person who intentionally helps the principal commit a crime is called an accomplice.
Note that an accomplice generally does not have to commit the crime itself, but can still face the same penalties as the principal if convicted. This is the case under both federal law and Massachusetts law.
Accessory Before/After the Fact
An accomplice who aids and abets a principal before the crime is committed can be called an accessory before the fact.
Compare that to an accessory after the fact: someone who knows that a person has committed a crime and attempts to either conceal the crime or the criminal from law enforcement.
A Few Caveats
Depending on the facts and the wording of the law, co-conspirators can also be charged as accomplices, making them punishable for the conspiracy charge in addition to their role in the commission of the actual crime.
Note, however, that conspirators can be found guilty even if the goal of the conspiracy is not actually completed. But to be convicted as an accomplice to a crime, the crime itself must actually have been carried out.