He's a pest who presumes he's in charge
Though no guest, into rooms he will barge
Off the beam and obsessive,
He's extremely possessive
You're hard pressed, and he looms very large.
Betty Grable and the menacing shadow of Laird Cregar in I Wake Up Screaming (Bruce Humberstone; 1941). Cregar plays the very first in a long line of obsessed cops in film noir -- and does it brilliantly.