Looking for the Black Arrow Killer

Hint: What should I ask Louie?

Hint: Where do I find Crazy Gary?

Nested hint: What does Crazy Gary want?
(sorry, cannot decode section)
Hint: Can I do something with the key I got from Dag Horton's Office?

Hint: I'm back on the street and lost the Black Arrow Killer.

Hint: How do I catch the Black Arrow Killer?