"Accessory after the fact" is a legal term that can be used to charge people who knowingly help a person who has committed a crime. Being charged with this crime may mean facing charges similar to the crime was that was committed by someone. For example, helping a murderer after he has committed a crime could make someone an accessory to murder, even if that person had nothing to do with the crime.
One of the reasons this charge exists, and it may be differently named or perceived differently in a variety of jurisdictions, is to discourage people from giving aid to those who commit crimes. There are a number of ways to get charged with accessory after the fact. A person could give a criminal money so he could escape the law, hide information about a crime so that the criminal is not charged, hide the actual criminal or in some way harbor and shelter him or her so that the person committing the crime avoids arrest and prosecution.
An important thing is needed for a prosecutor to win an accessory after the fact case, and sometimes it’s not obtainable. It must be proven the person facing this charge knew a crime had occurred. That isn’t always the case. If Mr. Smith picks up a hitchhiker and drops him off down the road without realizing the hitchhiker had just robbed an ATM machine, it would hard to make a case that Mr. Smith is an accessory. He had no knowledge of the crime.
More grey area occurs when family members are charged with accessory after the fact. It’s possible that in sheltering or giving aid to someone who is a criminal, a person does absolutely no wrong in the eyes of the law. It all hinges on whether the person aided or sheltered confesses to the crime or whether the family member has some knowledge of it outside of a confession. This is a difficult thing for many people because strong protective feelings often exist toward family, especially adult children, and many people want to help their family members avoid prosecution.
Ultimately, the cost is often too great for a family member to become an accessory after the fact. It could mean being charged and sentenced to serve in jail for about half of the time the person who committed the crime will serve.