Detective Steve Carella of the 87th precinct had a pretty complete description of the man he was looking for:

The man was tall, blond, handsome — a powerhouse of strength and sex. Women gave him whatever he wanted.

And he made some strange requests.

After seducing a woman, he would ask her to have a small heart tattooed on her hand, to show the world that she belonged to him.

When the woman had been thus branded as his property — he murdered her.