All new issues are unassigned by default. If you wish to change this:
- Go to the General Configuration page of the Administration section. Now simply edit the configuration and turn OFF the 'Allow Unassigned Issues' flag. For more detail please refer to the documentation relating to this function.
By default, new projects also have their 'Default Assignee' set to 'Unassigned.' This is located in the Roles section and can be changed there.