Green’s Dictionary of Slang

(US) acting in a thuggish manner; resembling a thug.

1960		G. Swarthout Where the Boys Are 4: Two hoody boys [...] put on a race one night with their cars full of kids and smashed up.
1967		J. Rechy Numbers (1968) 28: With ‘her’ is a hoody-looking youngman, obviously a hustler.
1981		M. Baker Nam (1982) 8: There was a part of town where there were a few hoody guys, but I always kept my distance.