Instead of deleting the second record, it is preferable to merge the two records by following the steps below:
Click Patients > Patient List.
Search for the duplicated record and click it.
From the patient's General page, click Edit at the top-right of the screen.
Click Merge at the top-right of the screen.
Enter the name of the destination record (the current patient's record will become part of the destination record's file).
Click Next. A list will appear, displaying all of the records to be merged.
Click OK to complete the merge.
Once this is complete, the current patient's record will become part of the destination record. This cannot be undone.