This isn’t true. Harboring someone from the police after they commit a crime makes you an accessory, not a primary.

Edit: to be more concrete and actually cite what I’m saying (my bad), we’ll use federal law since they clearly crossed state lines multiple times in the stages of committing this act of heroism crime:

An accessory after-the-fact is someone who, knowing a crime was committed, receives, relieves, comforts, or assists the offender or in any manner aids them to escape arrest or punishment. See: U.S. v. Triplett, 92 F.2d 1174 (5th Cir. 1991). The aid provided by the defendant to the principal must be given after the principal completes the crime.

The basic elements the government must demonstrate to prove that a defendant was an accessory after-the-fact are: (1) the commission of an underlying crime against the United States; (2) the defendant’s knowledge of that offense; and (3) assistance by the defendant in order to prevent the apprehension, trial, or punishment of the offender. See: U.S. v. White, 135 S. Ct. 1573, 191 L. Ed. 2d 656 (2015); Ellis v. U.S., 806 F. Supp. 2d 538 (E.D. N.Y. 2011).