Hi Amelia,
If he continued looking at you after he walked passed you, there is a chance that he likes you.
To be sure, make sure the next time you leave your apartment, you are alone.
If he shows up, make eye contact and smile at him.
He may be more willing to introduce himself to you when he notices that you are alone and that you have an inviting smile.
If he doesn’t try to talk to you, he may not like you.
If he returns your smile and stops to talk to you, there is a good chance that he likes you.