Only Administrators (read this article about Administrators, Administrators vs. Regular Care Professionals) can delete Seniors from their organization's SeniorGrowth databases.
To delete a Senior, access the Senior's profile (read this article, Editing Senior Profile) and click on the Admin tab, then on the Delete Senior button.
To confirm that you really want to delete a Senior and all the information related to him/her, including all the evaluations, you will have to confirm again. Be careful, deleting a Senior can not be undone.