diff --git a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/AbstractCommonAttributeSearcher.java b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/AbstractCommonAttributeSearcher.java
index 8f553dff2a..047ed4ed4d 100644
--- a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/AbstractCommonAttributeSearcher.java
+++ b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/AbstractCommonAttributeSearcher.java
@@ -130,9 +130,9 @@ public abstract class AbstractCommonAttributeSearcher {
         }
     }
 
-    static Map<Integer, CommonAttributeValueList> collateMatchesByNumberOfInstances(Map<String, CommonAttributeValue> commonFiles) {
+    static TreeMap<Integer, CommonAttributeValueList> collateMatchesByNumberOfInstances(Map<String, CommonAttributeValue> commonFiles) {
         //collate matches by number of matching instances - doing this in sql doesnt seem efficient
-        Map<Integer, CommonAttributeValueList> instanceCollatedCommonFiles = new TreeMap<>();
+        TreeMap<Integer, CommonAttributeValueList> instanceCollatedCommonFiles = new TreeMap<>();
 
         for (CommonAttributeValue md5Metadata : commonFiles.values()) {
             Integer size = md5Metadata.getDataSources().size();
diff --git a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/CommonAttributeCountSearchResults.java b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/CommonAttributeCountSearchResults.java
index c1d2dcb481..9eda2b4020 100644
--- a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/CommonAttributeCountSearchResults.java
+++ b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/CommonAttributeCountSearchResults.java
@@ -25,6 +25,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.TreeMap;
 import java.util.logging.Level;
 import org.sleuthkit.autopsy.centralrepository.datamodel.CorrelationAttributeInstance;
 import org.sleuthkit.autopsy.centralrepository.datamodel.CorrelationAttributeNormalizationException;
@@ -41,7 +42,7 @@ final public class CommonAttributeCountSearchResults {
     private static final Logger LOGGER = Logger.getLogger(CommonAttributeCountSearchResults.class.getName());
 
     // maps instance count to list of attribute values. 
-    private final Map<Integer, CommonAttributeValueList> instanceCountToAttributeValues;
+    private final TreeMap<Integer, CommonAttributeValueList> instanceCountToAttributeValues;
     private final int percentageThreshold;
     private final int resultTypeId;
 
@@ -58,7 +59,7 @@ final public class CommonAttributeCountSearchResults {
      */
     CommonAttributeCountSearchResults(Map<Integer, CommonAttributeValueList> metadata, int percentageThreshold, CorrelationAttributeInstance.Type resultType) {
         //wrap in a new object in case any client code has used an unmodifiable collection
-        this.instanceCountToAttributeValues = new HashMap<>(metadata);
+        this.instanceCountToAttributeValues = new TreeMap<>(metadata);
         this.percentageThreshold = percentageThreshold;
         this.resultTypeId = resultType.getId();
     }
@@ -73,7 +74,7 @@ final public class CommonAttributeCountSearchResults {
      */
     CommonAttributeCountSearchResults(Map<Integer, CommonAttributeValueList> metadata, int percentageThreshold) {
         //wrap in a new object in case any client code has used an unmodifiable collection
-        this.instanceCountToAttributeValues = new HashMap<>(metadata);
+        this.instanceCountToAttributeValues = new TreeMap<>(metadata);
         this.percentageThreshold = percentageThreshold;
         this.resultTypeId = CorrelationAttributeInstance.FILES_TYPE_ID;
     }
diff --git a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/InterCaseSearchResultsProcessor.java b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/InterCaseSearchResultsProcessor.java
index 52f2cec276..e2dc8e616b 100644
--- a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/InterCaseSearchResultsProcessor.java
+++ b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/InterCaseSearchResultsProcessor.java
@@ -29,6 +29,7 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.List;
 import java.util.Map;
+import java.util.TreeMap;
 import java.util.logging.Level;
 import org.sleuthkit.autopsy.casemodule.Case;
 import org.sleuthkit.autopsy.centralrepository.datamodel.CorrelationAttributeInstance;
@@ -173,7 +174,7 @@ final class InterCaseSearchResultsProcessor {
         } catch (EamDbException | TskCoreException ex) {
             LOGGER.log(Level.SEVERE, "Error accessing EamDb processing CaseInstancesTable.", ex);
         }
-        return new HashMap<>();
+        return new TreeMap<>();
     }
 
     /**
@@ -205,7 +206,7 @@ final class InterCaseSearchResultsProcessor {
         } catch (EamDbException | TskCoreException ex) {
             LOGGER.log(Level.SEVERE, "Error accessing EamDb processing CaseInstancesTable.", ex);
         }
-        return new HashMap<>();
+        return new TreeMap<>();
     }
 
     /**
@@ -248,7 +249,7 @@ final class InterCaseSearchResultsProcessor {
      */
     private class InterCaseByCountCallback implements CaseDbAccessManager.CaseDbAccessQueryCallback, InstanceTableCallback {
 
-        private final Map<Integer, CommonAttributeValueList> instanceCollatedCommonFiles = new HashMap<>();
+        private final TreeMap<Integer, CommonAttributeValueList> instanceCollatedCommonFiles = new TreeMap<>();
         private final int caseID;
         private final int targetCase;
 
@@ -311,7 +312,7 @@ final class InterCaseSearchResultsProcessor {
         }
 
         Map<Integer, CommonAttributeValueList> getInstanceCollatedCommonFiles() {
-            return Collections.unmodifiableMap(instanceCollatedCommonFiles);
+            return Collections.unmodifiableSortedMap(instanceCollatedCommonFiles);
         }
     }
 
diff --git a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/IntraCaseCommonAttributeSearcher.java b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/IntraCaseCommonAttributeSearcher.java
index f48d23d030..21ac1bb18b 100644
--- a/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/IntraCaseCommonAttributeSearcher.java
+++ b/Core/src/org/sleuthkit/autopsy/commonpropertiessearch/IntraCaseCommonAttributeSearcher.java
@@ -26,6 +26,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 import org.sleuthkit.autopsy.casemodule.Case;
 import org.sleuthkit.autopsy.casemodule.NoCurrentCaseException;
 import org.sleuthkit.autopsy.centralrepository.datamodel.EamDbException;
@@ -137,7 +138,7 @@ public abstract class IntraCaseCommonAttributeSearcher extends AbstractCommonAtt
             }
         }
 
-        Map<Integer, CommonAttributeValueList> instanceCollatedCommonFiles = collateMatchesByNumberOfInstances(commonFiles);
+        TreeMap<Integer, CommonAttributeValueList> instanceCollatedCommonFiles = collateMatchesByNumberOfInstances(commonFiles);
 
         return new CommonAttributeCountSearchResults(instanceCollatedCommonFiles, this.frequencyPercentageThreshold);
     }