Criminal sociopath.
A person who commits a crime is known as a criminal.
Depending on the circumstances, a person can be called an “accessory” to the crime, for harboring a fugitive. The person is an accessory to a crime if the person: Conceals or destroys evidence of the crime, or Harbors or conceals the person committing the crime.
a witness
a witness
They are called the Coroner.
Such a person would be an accomplice or a partner in crime.
an accessory after the fact may be what you are looking for
greedy, unethical, with out shame or morals
It depends on whether they think the person is part of the crime as well. If they do, then the person is called an accomplice... someone who helped the suspect commit the crime. If not, then the person is just an associate... someone who knows the suspect and might be able to identify where he or she is.
When someone encourages or helps another person to commit an illegal act or crime, it is called "aiding and abetting." And, yes, you can be prosecuted for it.
It is called embezzlement.
That person is an accessory or an accomplice.