When is the status set to ASSIGNED?
In some bug workflows, QA assigns NEW bugs to developers (by setting the Assigned To field), and then developers accept the assignment by changing the status field to ASSIGNED. In our workflow, we usually just CC a developer and allow them to assign the bug to themselves if they'd like to tackle it.
In some cases someone will ask you to assign a bug directly to them -- e.g. "Please create a bug about XYZ and assign it to me" or "Yeah, I'll take that bug; please assign it to me." In such cases, there won't need to be a two-step process: The developer has already agreed to accept the bug.