Hello Detectives.
I'm very sorry to tell you all about the next update is delayed for 2 days. The reason for the delay is me misjudged the time taking for the photo mechanism. That's part is done, finally.

Since the questionable part has decided. Let's look at how to take a photo and make progress.

CAPTURE THE CLUES

Here is a video about how the whole photo-taking system works.
On the left bottom corner is the lens of the camera, the frame on the right will be the previous photo the detective just shot.  The control in the video is very like google street. Drag mouse to pan the camera, press P (temporary shortcut, will be also a button on-screen) to active the photo mode. In the photo mode, click on the area that caused the detective (here means you) interest to take a photo. 

PHOTO TO PROGRESS

Whenever the detective took a photo, also draw all the information on the scene onto the photo. Every track and clue is containing a script that stored Clue Name, Clue Description, Hashtag information.

Now take a look at the words written in Hashtag.

Here, "Human is safe|2" means that you need 2 photos with the tag "Human is safe" to make the detective have a theory of the human involved is safe. There will be more than 2 clues on the scene. The fulfilled Hashtag will become a bullet point as "- Human is safe" in the note book, which can become a key knowledge to the Contact Stage. 

"Outsider|4" indicates that this clue is much harder to clarify and thus need 4 photos. There will be a hint to show how hard it is later on.

I try to avoid the situation where if you can't find all the elements of the story then you can't get into the next stage. Instead, you found just enough will be fine at most of the case. 

P.S:
This is the technical part of how I lost 2 days.
I stuck on how to load the photo to the material of the UI for 2 days. Find out it was a very dump stuck. I gave the texture slot of the main shader a name "BaseColor", but the visual scripting tool don't accept a custom name and has to use the ID of the slot.
Thanks to a friend talk me through it and give me a fresh view.