Murder in the Gunroom by H. Beam Piper

Rand found another car, a smoke-gray Plymouth coupe, standing on the left of his Lincoln when he went down to the garage. Running his car outside and down to the highway, he settled down to his regular style of driving -- a barely legal fifty m.p.h., punctuated by bursts of absolutely felonious speed whenever he found an unobstructed straightaway. Entering Rosemont, he slowed and went through the underpass at the railroad tracks, speeding again when he was clear of the village. A few minutes later, he was turning into the crushed-limestone drive that led up to the buff-brick Gresham house.

A girl met him at the door, a cute little redhead in a red-striped dress, who gave him a smile that seemed to start on the bridge of her nose and lift her whole face up after it. She held out her hand to him.