Sales Cloud - where do I write custom logs?

Summary:

Need to know where to write custom log information from groovy script triggers on an object

Content (required):

Use case: We have a an object trigger on create of Service Request standard object. It is not currently behaving as expected, so I would like to output println messages in between lines of script execution to narrow down the problem.

The problem is that runtime messages in sandbox will only show records triggered by me (currently logged in user). I need runtime messages to show println statements when ANY user triggers the create of a Service Request. For this reason I cannot use the debugger either, because the debugger only activates when I myself create the record in question (thus being completely useless when the record is created by an API call i.e a different user, for example).