Twitter recently changed some of their rules for app authorization using OAuth, so as a result, when a new user tries to start Detective, they will get an error when authorizing Twitter. However, if you’re already using Detective it will continue to work as long as you don’t log out of Twitter.
Detective uses MGTwitterEngine, which no longer seems to be actively maintained and which still uses Twitter’s deprecated 1.0 API. As a result, at some point it would stop working when Twitter shuts off that API. I’ve looked into a few options and I’ve determined that the best way to move forward is to use Mac OS X’s built-in social framework. Rather than asking you to log in to Twitter, it will now use your Mac’s twitter accounts. However this means we will no longer be able to support any Mac OS X version earlier than 10.8. I hope to have an update available soon.