There are 12 Black Cat Stakeouts in the game. This video shows the locations and solutions to 11 of them. The first one is part of the story and unmissable. The remaining 11 get marked on the map. Once you reach the photo spot, you must find the hidden doll in the viewable area. After getting all of them you get to track down Black Cat’s hideout. This one will be shown on the map via a quest marker. Once you find Black Cat’s hideout you get two rewards: the Dark Suit and the Cat Prints silver trophy.
Here is a video guide with English commentary!
Here is a playlist of guides for this game!
https://www.youtube.com/playlist?list=PL-HeW6XkKdULV1kVJliBp...