Killer's Wedge by Ed McBain (Permabooks, 1959)

 

SQUADROOM 87TH PRECINCT 

Four cops getting through a routine day.  Complaints, interrogations, reports--holdups, beatings, rapes, murders.

Then in walks a dame in black.

"Yes?" asks Detective Cotton Hawes.

She reaches into her coat pocket and pulls out a cold, hard object.

"This is a .38," she says and points it at the four men.  "Give me your guns."

"Look, Lady," says Hawes, "put up the piece.  The joke's not funny."

The dame's eyes narrow to slits.  "Shut up, Copper.  I've come here to kill.  One phony move and I keep shooting until every man in this place is dead."

And the award for All Time Most Awkward Posture goes... to the "dame" on the front cover.   Seriously.  I think she's supposed to have one of her feet resting on a chair rung, but it looks like she's doing some kind of seated can can dance.

(Incidentally, at no time in this book is she referred to as a "dame".  We're spared that cliché at least.  Nor do the cops in the book commit any beatings, rapes or murders.  It's not that kind of story!)