We're using the free version of Jira for our project. With free Jira you're unable to edit any permissions beyond their default setting. Still, the default permission says that Administrators are the only roles that can delete issues. I am Administrator and own the board. I am able to delete the project, yet there is no delete option I can find anywhere for deleting issues.
We need to delete an issue because it is a duplicate. This is not a case of having it there as a good practice just in case -- the creation of the issue was human error, and we understand it will be gone forever.