Tip for the final showdown of a campaign: you cant box knocked out targets.
Allows for some easy cheese 
- Ko a suspect near a box, if you can’t box him it’s the Leader, and you kill him.
- If you can box him it’s not the leader, but will drop a burner phone.
- Use the phone and other suspects will come over.
Repeat
Those phones to set up a meeting are very good in that regard.