How do I delete an assignment submission as an admin?
As an admin, you can delete a student's assignment submission in SpeedGrader. This allows you to manage inappropriate submissions or submissions that otherwise need to be removed from a course.
Note: The option to delete assignment submissions is only available to admins that have been granted the Users - Act As permission.
In Global Navigation, click the Admin link , then click the name of the account .
To find the course in the account, you can use the course filters  or search options .
To open a course, click the name of the course you want to open .
In Course Navigation, click the Assignments link.
To confirm you want to delete the submission file, click the OK button.