An accessory after the fact is a person who (1) assists someone who has committed a crime, (2) after the commission of the crime, (3) with knowledge that the person committed the crime, and (4) with the intent to help the person who committed the crime avoid arrest or punishment. The United States Code defines an accessory after the fact has someone who knows a crime has been committed and receives the offender (harbors them), or relieves, comforts, or assists the offender in order to hinder or prevent the offender’s apprehension, trial, or punishment.

An accessory after the fact is different that an accomplice to a crime, who helps with the commission of the crime. An accessory after the fact is treated as a criminal offense separate from the criminal offense of the offender being assisted, and may be prosecuted as the criminal offense of obstruction of justice.

In Kansas, an accessory after the fact is defined under state law as someone who knowingly gives assistance to a person who has committed a felony, with the intent to enable that person to avoid arrest, trial, conviction, or punishment. This is covered under Kansas Statutes Annotated (K.S.A.) 21-5301. The statute distinguishes between an accessory after the fact and an accomplice, where the latter is involved in the commission of the crime. Being an accessory after the fact is a separate offense and can be charged independently of the principal crime. It is often prosecuted under the broader category of obstructing justice, which includes actions that interfere with the enforcement and administration of laws. Penalties for being an accessory after the fact vary depending on the severity of the original crime committed and other circumstances surrounding the individual's involvement.