diff --git a/static/js/app/users.js b/static/js/app/users.js
index 14dc7d5d..354b5e87 100644
--- a/static/js/app/users.js
+++ b/static/js/app/users.js
@@ -94,14 +94,11 @@ function edit(idx) {
         },
         done: function(e, data) {
             $.each(data.result, function(i, record) {
-                targets.DataTable()
-                    .row.add([
-                        escapeHtml(record.first_name),
-                        escapeHtml(record.last_name),
-                        escapeHtml(record.email),
-                        escapeHtml(record.position),
-                        '<span style="cursor:pointer;"><i class="fa fa-trash-o"></i></span>'
-                    ]).draw()
+                addTarget(
+                    record.first_name,
+                    record.last_name,
+                    record.email,
+                    record.position);
             });
         }
     })
@@ -117,6 +114,35 @@ function deleteGroup(idx) {
     }
 }
 
+function addTarget(firstNameInput, lastNameInput, emailInput, positionInput) {
+    // Create new data row.
+    var email = escapeHtml(emailInput).toLowerCase();
+    var newRow = [
+        escapeHtml(firstNameInput),
+        escapeHtml(lastNameInput),
+        email,
+        escapeHtml(positionInput),
+        '<span style="cursor:pointer;"><i class="fa fa-trash-o"></i></span>'
+    ];
+
+    // Check table to see if email already exists.
+    var targetsTable = targets.DataTable();
+    var existingRowIndex = targetsTable
+        .column(2, {order: "index"}) // Email column has index of 2
+        .data()
+        .indexOf(email);
+
+    // Update or add new row as necessary.
+    if (existingRowIndex >= 0) {
+        targetsTable
+            .row(existingRowIndex, {order: "index"})
+            .data(newRow);
+    } else {
+        targetsTable.row.add(newRow);
+    }
+    targetsTable.draw();
+}
+
 function load() {
     $("#groupTable").hide()
     $("#emptyMessage").hide()
@@ -168,30 +194,28 @@ function load() {
 
 $(document).ready(function() {
     load()
-        // Setup the event listeners
-        // Handle manual additions
+    // Setup the event listeners
+    // Handle manual additions
     $("#targetForm").submit(function() {
-            targets.DataTable()
-                .row.add([
-                    escapeHtml($("#firstName").val()),
-                    escapeHtml($("#lastName").val()),
-                    escapeHtml($("#email").val()),
-                    escapeHtml($("#position").val()),
-                    '<span style="cursor:pointer;"><i class="fa fa-trash-o"></i></span>'
-                ])
-                .draw()
-            $("#targetForm>div>input").val('')
-            $("#firstName").focus()
-            return false
-        })
-        // Handle Deletion
+        addTarget(
+            $("#firstName").val(),
+            $("#lastName").val(),
+            $("#email").val(),
+            $("#position").val());
+
+        // Reset user input.
+        $("#targetForm>div>input").val('');
+        $("#firstName").focus();
+        return false;
+    });
+    // Handle Deletion
     $("#targetsTable").on("click", "span>i.fa-trash-o", function() {
         targets.DataTable()
             .row($(this).parents('tr'))
             .remove()
             .draw();
-    })
+    });
     $("#modal").on("hide.bs.modal", function() {
-        dismiss()
-    })
-})
+        dismiss();
+    });
+});