From "The Gumshoe, the Witch and the Virtual Corpse":
My client had just walked in through the hotel's big front doors. She was wearing a trench coat and dark sunglasses, a look that screamed "PLEASE! I am trying not to be recognized!" She'd capped off the ensemble with a huge floppy hat. On the plus side, it did succeed in covering half of her face. But on the down side, the thing was so damn ridiculous that it called even more attention to her. Apparently her mother had never taught her how to properly accessorize for a stake-out.
The two Gumshoe books, in order, are:
The Gumshoe, the Witch and the Virtual Corpse