“The non-repentant evil person” was never truly saved in the first place then! Jesus is not going to lose his ‘sheep’ or his ‘gold coins’ (see Matthew 18:12-14 and Luke 15:1-10); He loves us all so much that He died for us. He also gave us free will—we can accept Him or deny Him. He doesn’t force us to do anything.
This younger man believed in Christ, but as he became more mature and found spiritual nourishment in alcohol, marijuana, criminality and meth, he became quite the demon.
Can a person like that eventually redeem himself with a real reaffirmation of his faith? Sure.
Is someone like that equally as secure with their place in heaven as they were when younger after all their criminality without genuine repentance? That is up to God, but I do not think there will be some completely free pass unless the sinner themselves make steps in the right direction that are sincere.