What are the implications for letting someone stay with you that you know has multiple felonies?

If you are hiding the person from law enforcement, you could be held as an accessory after the fact. You could also be charged with obstruction of justice, hindering an investigation, harboring a fugitive, etc.

If you are hiding the person from the bail bondsman, ouch. You face all the criminal problems plus the wrath of the bondsman, and they can be a bit annoying when they don't appreciate your behavior.

If you are letting someone stay with you who has committed crimes that are, as yet, undiscovered or have not been associated with that person, you could still end up being an accessory.

If you are letting someone on parole or probation stay with you, the major risk is that the person will re-offend. If you are allowing a dangerous person to stay near vulnerable people, you could wind up with civil penalties. You would need to talk to the parole officer directly to discuss the implications of having the person stay with you.

If the person is continuing with their criminal activities and is under surveillance you may find your home the subject of a search warrant with the police rummaging through your possessions looking for evidence.

The person may have enemies, or visitors, that risk your home being visited by people you don't normally associate with.