If you can't see the record in the Mosaic front end, it's because the record was previously deleted.
Check the MO_DELETED_PERSONS for an entry matching the person id and make a note of the DELETED_ON date (replacing <person_id> with the actual person id)
select * from MO_DELETED_PERSONS where person_id = '<person_id>'
Then compare this with the DATETIME_OF_REQUEST column in the MO_PERSON_DELETE_REQUESTS (replacing <person_id> with the actual person id)
select * from MO_PERSON_DELETE_REQUESTS where person_id = '<person_id>'