diff --git a/app/helpers/audit_helper.rb b/app/helpers/audit_helper.rb
index 0eb913dfa..3762c1a86 100644
--- a/app/helpers/audit_helper.rb
+++ b/app/helpers/audit_helper.rb
@@ -3,7 +3,7 @@ def display_audit_value(value, field)
     return "(none)" if value.blank?
     return Questionnaire::POSSIBLE_ACC_STATUS[value] if field == "acc_status"
     return BusList.find(value)&.name || value if field == "bus_list_id"
-    return User.find(value)&.full_name || value if field == "checked_in_by_id"
+    return User.find_by_id(value)&.full_name || "(deleted user)" if field == "checked_in_by_id"
     return value.join(", ") if value.is_a? Array
     return display_datetime(value, relative: false) if value.is_a? Time
 
diff --git a/app/models/questionnaire.rb b/app/models/questionnaire.rb
index 024097343..0f692613a 100644
--- a/app/models/questionnaire.rb
+++ b/app/models/questionnaire.rb
@@ -159,7 +159,7 @@ def date_of_birth_formatted
 
   def acc_status_author
     return unless acc_status_author_id.present?
-    User.find(acc_status_author_id)
+    User.find_by_id(acc_status_author_id)
   end
 
   def checked_in?
@@ -172,7 +172,7 @@ def boarded_bus?
 
   def checked_in_by
     return unless checked_in_by_id.present?
-    User.find(checked_in_by_id)
+    User.find_by_id(checked_in_by_id)
   end
 
   def fips_code
diff --git a/app/views/manage/questionnaires/_checkin_card.html.haml b/app/views/manage/questionnaires/_checkin_card.html.haml
index ed67a53c8..4a237f320 100644
--- a/app/views/manage/questionnaires/_checkin_card.html.haml
+++ b/app/views/manage/questionnaires/_checkin_card.html.haml
@@ -5,7 +5,13 @@
       = render 'manage/questionnaires/check_in_badge'
       - if @questionnaire.checked_in_at
         %small
-          = @questionnaire.checked_in_by_id ? @questionnaire.checked_in_by.email : "(never checked in)"
+          - if @questionnaire.checked_in_by_id
+            - if @questionnaire.checked_in_by
+              = @questionnaire.checked_in_by.email
+            - else
+              = "(deleted user)"
+          - else
+            = "(never checked in)"
           = @questionnaire.checked_in_at ? display_datetime(@questionnaire.checked_in_at, in_sentence: true) : "(not checked in)"
     - if !@questionnaire.checked_in_at
       %p.card-text
diff --git a/app/views/manage/questionnaires/show.html.haml b/app/views/manage/questionnaires/show.html.haml
index a934d65bc..429872c48 100644
--- a/app/views/manage/questionnaires/show.html.haml
+++ b/app/views/manage/questionnaires/show.html.haml
@@ -32,7 +32,13 @@
         %p.card-text
           = render 'acc_status_badge'
           %small
-            = @questionnaire.acc_status_author_id ? @questionnaire.acc_status_author.email : "(no author)"
+            - if @questionnaire.acc_status_author_id
+              - if @questionnaire.acc_status_author
+                = @questionnaire.acc_status_author.email
+              - else
+                = "(deleted user)"
+            - else
+              = "(no author)"
             = @questionnaire.acc_status_date ? display_datetime(@questionnaire.acc_status_date, in_sentence: true) : "(no date)"
         - if current_user.admin?
           = bs_vertical_simple_form @questionnaire, url: url_for(action: "update_acc_status", controller: "questionnaires") do |f|
diff --git a/test/models/questionnaire_test.rb b/test/models/questionnaire_test.rb
index cb60e67ea..e89c026f8 100644
--- a/test/models/questionnaire_test.rb
+++ b/test/models/questionnaire_test.rb
@@ -204,6 +204,13 @@ class QuestionnaireTest < ActiveSupport::TestCase
       assert_nil questionnaire.acc_status_author
     end
 
+    should "return nil if author deleted" do
+      user = create(:user, email: "admin@example.com")
+      questionnaire = create(:questionnaire, acc_status_author_id: user.id)
+      user.destroy
+      assert_nil questionnaire.acc_status_author
+    end
+
     should "return the questionnaire's user" do
       user = create(:user, email: "admin@example.com")
       questionnaire = create(:questionnaire, acc_status_author_id: user.id)
@@ -402,6 +409,13 @@ class QuestionnaireTest < ActiveSupport::TestCase
       assert_nil questionnaire.checked_in_by_id
     end
 
+    should "return no one if user who checked-in questionnaire is deleted" do
+      user = create(:user)
+      questionnaire = create(:questionnaire, checked_in_by_id: user.id)
+      user.destroy
+      assert_nil questionnaire.checked_in_by
+    end
+
     should "return user who checked in ther questionnaire" do
       user = create(:user)
       questionnaire = create(:questionnaire, checked_in_by_id: user.id)