Will believes Riggs shot Shawn for a few main reasons:
- Motive: Will thinks Riggs had a reason to target Shawn, possibly due to past conflicts or grievances.
- Opportunity: Will suggests that Riggs was in the right place at the right time to commit the crime.
- Behavior: Will notices suspicious behavior from Riggs that makes him doubt Riggs' innocence.
- Witnesses: There may be witnesses or evidence that link Riggs to the shooting.
Overall, Will connects these dots to form his belief that Riggs is responsible for Shawn's shooting.