How to automatically re-assign a Defect to the value of the Defect Owner when Status = Resolved?

At the time the Status of a Defect is set to "Resolved" I'd like to have the "Assigned To" field automatically populated with the Defect Owner rather than a manual process.  I've looked at accomplishing this via an Escalation Rule but no luck there.  I then tried Workflows and came up blank there too.  I could accomplish this in either of the above options if the value of the Defect Owner could be populated within the drop-downs but unfortunately that data isn't included in the list.  Any suggestions would be greatly appreciated.