When a federal court charges a Missouri resident with the crime of accessory, it does so because that person either helped someone commit a crime or provided emotional, physical or financial assistance post-crime. Physical assistance includes concealment. The law refers to concealing someone after he or she has committed a crime as "harboring a fugitive." Harboring a fugitive is a federal offense and is punishable as such.
According to The United States Department of Justice, concealing a person from arrest or an escaped prisoner after having received notice or knowledge of the person's status is a crime punishable by imprisonment of up to one year. However, if the warrant or notice of arrest for the fugitive or person in question is for a felony charge, the person who harbors him or her may face a maximum term of imprisonment of five years. In addition to prison time, the offender will likely receive a fine from the court for obstructing justice.
If a person harbors or conceals a prisoner after his or her escape from the custody of a federal penal or correctional facility or from the Attorney General, he or she may receive a prison sentence of up to three years.
According to ThoughCo., there are several ways in which the prosecution will attempt to prove accessory after the fact. There are also two defenses a person can use to combat the charges.
To prove accessory after the fact, the prosecutor will try to prove four elements to be true. The first is that the principal committed a crime. Next, the prosecution will try to prove that the defendant knew the principal both committed the act and was either charged or convicted of said act. Then, it will attempt to prove that after the state either charged or convicted the principal, the defendant concealed or aided him or her. Finally, the prosecution must prove that the defendant assisted the principal with the express purpose of helping him or her hide from justice.
One can defend oneself against the charge of harboring a fugitive by either claiming to have no knowledge of the crime or by proving lack of intent. If one can show that he or she did not help the principal with the intent to help him or her circumvent capture, trial, conviction or penalty, the defendant may avoid criminal charges.