Checking for the duplicate record is not a feature that can be applied in the scenario you are discussing. This feature is part of Security Assist but just for the user registration.
To craft this yourself you would create a new recordset that looks at the columns in your staff table. In the filter portion you would need to specify the person_id = form value, then enter the name of your input that has the person id. This is the same field you would specify in the insert for the person_id.
You would then just put in your insert server behavior like normal. Once it is on the page you can just put an if statement around it that checks to see if there are any rows in this recordset to check for duplicates. If there are not any records in it then there are no duplicates and you can continue with the insert like normal. The if statement would look something like this:
<?php if (!($totalRows_rsDuplicates >= 1)){?>
your insert server behavior here
<?php } else { ?>
header("Location: " . $your_redirect_page);
<?php } ?>
In here if there is not any rows in the recordset the insert will occur like normal. If there are records in the recordset then you will be redirect to whatever page you specify in the header call. This is just a start of what it would look like for you, the specifics will probably be different for you but the structure and idea are the same. Getting this implemented will require some custom coding as it is not a supported feature of the tools.
