What constitutes the crime of accessory after the fact?

Penal Code section 32 defines the crime of accessory after the fact: "Every person who, after a felony has been committed, harbors, conceals or aids a principal in such felony, with the intent that said principal may avoid or escape from arrest, trial, conviction or punishment, having knowledge that said principal has committed such felony or has been charged with such felony or convicted thereof, is an accessory to such felony." The crime of accessory consists of the following elements: (1) a principal, someone other than the defendant, must have committed a specific, completed felony; (2) the defendant must have harbored, concealed, or aided the principal; (3) with knowledge that the principal committed the felony or has been charged or convicted of the felony; and (4) with the intent that the principal avoid or escape from arrest, trial, conviction, or punishment. (People v. Plengsangtip (2007) 148 Cal.App.4th 825, 836.)