Accomplices, Accessories, Aiders, and Abettors

Anyone who intentionally participates in a crime or helps a criminal before or after the crime may be held responsible for it.

Often people participate in crimes in different ways and to different degrees. For instance, in a bank robbery, one person may enter the bank and conduct the holdup, while another person is waiting in the getaway car and a third person is positioned at a different location as a spotter.

Principals and Accomplices

As a general rule, the law refers to the main actor in a crime as the principal and to assisting persons as accomplices. Technically, an accomplice is one who intentionally helps another to commit a crime.

Even if an accomplice does not carry out the crime, in the eyes of the law the accomplice's pre-crime assistance makes him or her just as guilty as the person who does the deed itself. For example, assume that Lars Senny breaks into a warehouse and steals property belonging to the warehouse owner. Hal Perr would be Lars's accomplice and just as guilty as Lars if Hal takes any of the following steps to assist Lars to commit the theft:

  • Hal works in the warehouse and drugs the warehouse nightwatchman before leaving work on the day of the theft.
  • Hal cuts the wires to the burglar alarm (or cuts a hole in the fence) so that Lars can enter the warehouse without being detected.
  • Hal is a designer of warehouses and meets with Lars a week before the theft to review warehouse layouts and exit routes.
  • Hal rents a U-Haul and parks it outside the warehouse on the night of the robbery.
  • Knowing what Lars has in mind, Hal agrees to babysit for Lars's infant child while Lars goes to the warehouse.

To prove that a defendant is an accomplice, the government must prove that he or she intentionally aided in the commission of a crime. This means that the defendant must realize that the principal is going to commit a crime and that the accomplice intends to help the crime succeed.

Accomplices, Accessories, Aiders and Abettors, and Principals

To distinguish the criminal culpability of one from another, the common law developed specialized terms for the various ways in which one could be an accomplice. For instance, a "principal in the first degree" was the person who actually carried out a crime. A "principal in the second degree" (an "aider and abettor") was a helper who was present at a crime scene but in a passive role, such as acting as a "lookout." An "accessory before the fact" was a helper who was not present at the crime scene. While some state laws retain the common law terminology, few states make any distinction between the criminal liability of crime perpetrators and their accomplices. All can be punished equally, whether they actually perpetrate a crime or only help bring it about.

Accessory After the Fact

An accessory after the fact is someone who, knowing that a felon has finished committing a crime (usually the crime has to be a felony), helps the felon avoid arrest or trial. In most states, accessories after the fact face far less punishment than accomplices or principals.


Conspirators are two or more people who agree to commit a crime. (The distinction between accomplices and conspirators is that the former are "helpers," while each conspirator is a principal.) Conspiracy is a controversial crime, in part because conspirators can be guilty even if the crime that they agree to commit never occurs. As a result, conspirators can be punished for their illegal plans rather than for what they actually do. As some protection against convicting people purely for their private thoughts, in most states conspirators are not guilty of the crime of conspiracy unless at least one of them commits an "overt act." An "overt act" is an activity that in some way moves a conspiracy into motion.