A person who is charged with aiding or abetting a crime, or being an accessory to a crime, is one who knowingly assisted a criminal commit a crime but who is usually not present at the time or place the crime was committed. Ways to aid a crime include action, advice or financial assistance. Legal definitions vary by state and if the level of involvement is high, an individual may be indicted with a more severe charge, such as conspiracy.
An example of aiding or abetting would be if Michael helped John plan a bank robbery by drawing out plans. Michael would also be considered an accessory if he helped John purchase equipment that he knew would be used in a robbery, or if he helped John stash the stolen money at his house.