So what actually is "Insight" in this game? "Insight" tells the player what level of evidence they have at a given time (use SELECT).

If you're wondering how it was programmed, this is the DevLog for you. 

The Insight is purposely vague, but it is simply a universal variable in GBStudio which interacting with clues or asking certain questions either adds to or takes away from the total. This is not totally known to the player, but it can be checked after certain interactions. In the background, if the player finds a clue which suggests the offender, the insight will increase greatly. If the player asks valuable questions, Insight increases as well. Some clues to not contribute to the total. Also, some questioning choices actually take away from the total. Towards the end, the player can meet back up with his cop buddy without having the total evidence. However, their final choice may not be that informed. 

In practical terms to set this up, use Math Functions in GBStudio.

MathFunctions>Select Variable>Operation: Add/Subtract>Value (Number). 

Now you have a running variable keeping track of evidence collection. Now you can use "If" and "Var Compare with Value", to control player movements and force progress.

Since you read to the end, to get out of the main sanctuary to meet up with the cop in charge, your Insight needs to be >=250 (there are much higher levels to achieve). In general, the trigger starts with: If(Insight=>250[Var Compare with Value], change scene if true, display dialogue "Keep on the case" if false).

I hope you found his helpful!