diff --git a/doorcontrol/admin.py b/doorcontrol/admin.py
index 3b76836..e817c17 100644
--- a/doorcontrol/admin.py
+++ b/doorcontrol/admin.py
@@ -3,11 +3,39 @@ from django.contrib import admin
 from .models import HIDEvent
 
 
+class IsRedFilter(admin.SimpleListFilter):
+    title = "Is Red"
+    parameter_name = "is_red"
+
+    def lookups(self, request, model_admin):
+        return (
+            ("1", "Yes"),
+            ("0", "No"),
+        )
+
+    def queryset(self, request, queryset):
+        if self.value() is None:
+            return queryset
+        else:
+            return queryset.filter(is_red=(self.value() == "1"))
+
+
 @admin.register(HIDEvent)
 class HIDEventAdmin(admin.ModelAdmin):
     search_fields = ["description", "forename", "surname", "cardholder_id"]
     list_display = ["door_name", "timestamp", "event_type", "description", "is_red"]
-    list_filter = ["door_name", "event_type"]
+    list_filter = [
+        "door_name",
+        "event_type",
+        IsRedFilter,
+    ]
+
+    def get_queryset(self, request):
+        return super().get_queryset(request).with_is_red()
+
+    @admin.display(boolean=True)
+    def is_red(self, obj):
+        return obj.is_red
 
     def has_add_permission(self, request, obj=None):
         return False
diff --git a/doorcontrol/models.py b/doorcontrol/models.py
index 935192e..345c858 100644
--- a/doorcontrol/models.py
+++ b/doorcontrol/models.py
@@ -1,8 +1,37 @@
-from django.contrib import admin
 from django.db import models
+from django.db.models import ExpressionWrapper, Q
+
+
+class HIDEventQuerySet(models.QuerySet):
+    def with_is_red(self):
+        """Based on `function isRedEvent` from /html/hid-global.js on a HID EDGE EVO Solo"""
+        return self.annotate(
+            is_red=ExpressionWrapper(
+                Q(
+                    event_type__in=[
+                        1022,
+                        1023,
+                        2024,
+                        2029,
+                        2036,
+                        2042,
+                        2043,
+                        2046,
+                        4041,
+                        4042,
+                        4043,
+                        4044,
+                        4045,
+                    ]
+                ),
+                output_field=models.BooleanField(),
+            )
+        )
 
 
 class HIDEvent(models.Model):
+    objects = HIDEventQuerySet.as_manager()
+
     class EventType(models.IntegerChoices):
         DENIED_ACCESS_CARD_NOT_FOUND = 1022, "Denied Access: Card Not Found"
         DENIED_ACCESS_ACCESS_PIN_NOT_FOUND = 1023, "Denied Access Access: PIN Not Found"
@@ -89,25 +118,6 @@ class HIDEvent(models.Model):
 
         return event_types.get(self.event_type, f"Unknown Event Type {self.event_type}")
 
-    @admin.display(boolean=True)
-    def is_red(self):
-        """Based on `function isRedEvent` from /html/hid-global.js on a HID EDGE EVO Solo"""
-        return self.event_type in [
-            1022,
-            1023,
-            2024,
-            2029,
-            2036,
-            2042,
-            2043,
-            2046,
-            4041,
-            4042,
-            4043,
-            4044,
-            4045,
-        ]
-
     def __str__(self):
         return f"{self.door_name} {self.timestamp} - {self.description}"