Bava Metzia 83b records that R’ Elazar son of R’ Shimon approached a Roman officer and asked him how he is successful at catching crafty criminals (citing a passuk to that effect). The guard asked him for advice, and this was R’ Elazar’s response:
עול בארבע שעי לחנותא כי חזית איניש דקא שתי חמרא וקא נקיט כסא בידיה וקא מנמנם שאול עילויה אי צורבא מרבנן הוא וניים אקדומי קדים לגרסיה אי פועל הוא קדים קא עביד עבידתיה ואי עבידתיה בליליא רדודי רדיד ואי לא גנבא הוא ותפסיה
Go at four hours in the day to the inn. If you see someone drinking wine, holding his cup, and dozing, ask about him. If he’s a Torah scholar, he’s dozing because he got up early to learn. If he’s a craftsman, he got up early to work. If he works at night, he thins out metals. If he’s none of them, he’s a thief, and you should grab him.
That’s an awfully incomplete list. Maybe he has a sleep disorder, like narcolepsy. (I see no reason to assume this is a new phenomenon that people have this.) How can he be so certain that people who aren’t craftsmen, scholars, or night workers must be thieves?