Also, only a woman would be likely to be wearing gloves on a warm summer night.

Indeed, coming from a distance by train, or car, she would certainly wear gloves.
She would not dream of coming to an interview, with a man with whom she had been intimate and whom she wished to bend to her will, with hands dirtied by a journey.
If that gloved hand had not been the hand of the mysterious woman, then the murder had been premeditated, and the murderer or murderess had put on gloves with the deliberate purpose of leaving no finger-prints.
It _was_ the woman.

In all probability it was the woman.
Then Mr.Flexen's sub-conscious mind began to jog his intellect.
Somewhere in his memory there was a fact he had noted about gloves, and that fact was now important in its bearing on the case.

He set about trying to recall it to his mind.

He was not long about it.