You must be logged in as an Admin user and have "Enable Delete On Person Data" privileges
1) Log in as a user with Admin role, and review the Admin role
You must have "Enable Delete On Person Data" checked
If not, enable it by checking it off, save it, and log out and log back in.
2) In the Rapid Registration look up the visitor using the inteli-hint >> select more info
3)
select the record >> click delete
4) select the person, and hit "Yes Delete this person"