diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2fd104b04..0eb794e3b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+### Development
+
+- Fix ConcurrentModificationException crash on background detection reported in #929. (#940, David G. Young)
+- Expedite beacon detections on Samsung when transitionoing from screen on to screen onff (#941, David G. Young)
+
 ### 2.16.3 / 2019-09-18
 
 - Fix thread leak with 0 regions and settings applied, (#888, David G. Young)
diff --git a/lib/src/main/java/org/altbeacon/beacon/service/ScanJob.java b/lib/src/main/java/org/altbeacon/beacon/service/ScanJob.java
index ede97b84f..062aab6ae 100644
--- a/lib/src/main/java/org/altbeacon/beacon/service/ScanJob.java
+++ b/lib/src/main/java/org/altbeacon/beacon/service/ScanJob.java
@@ -77,7 +77,7 @@ public void run() {
                     LogManager.i(TAG, "Running periodic scan job: instance is "+ScanJob.this);
                 }
 
-                List<ScanResult> queuedScanResults = ScanJobScheduler.getInstance().dumpBackgroundScanResultQueue();
+                List<ScanResult> queuedScanResults =  new ArrayList<>(ScanJobScheduler.getInstance().dumpBackgroundScanResultQueue());
                 LogManager.d(TAG, "Processing %d queued scan resuilts", queuedScanResults.size());
                 for (ScanResult result : queuedScanResults) {
                     ScanRecord scanRecord = result.getScanRecord();
diff --git a/lib/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScannerForLollipop.java b/lib/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScannerForLollipop.java
index 1cc98bbaf..2f53d2981 100644
--- a/lib/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScannerForLollipop.java
+++ b/lib/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScannerForLollipop.java
@@ -7,8 +7,10 @@
 import android.bluetooth.le.ScanFilter;
 import android.bluetooth.le.ScanResult;
 import android.bluetooth.le.ScanSettings;
+import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
+import android.content.IntentFilter;
 import android.os.Build;
 import android.os.ParcelUuid;
 import android.os.PowerManager;
@@ -199,7 +201,16 @@ protected void startScan() {
                             mBeaconManager.getBeaconParsers());
                 }
                 else {
-                    LogManager.d(TAG, "Using an empty scan filter since this is 8.1+ on Non-Samsung");
+                    if (Build.MANUFACTURER.equalsIgnoreCase("samsung")) {
+                        LogManager.d(TAG, "Using a wildcard scan filter on Samsung because the screen is on.  We will switch to a non-empty filter if the screen goes off");
+                        // if this is samsung, as soon as the screen goes off we will need to start a different scan
+                        // that has scan filters
+                        IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
+                        mContext.getApplicationContext().registerReceiver(mSamsungScreenOffReceiver, filter);
+                        LogManager.d(TAG, "registering SamsungScreenOffReceiver "+mSamsungScreenOffReceiver);
+                    } else {
+                        LogManager.d(TAG, "Using an empty scan filter since this is 8.1+ on Non-Samsung");
+                    }
                     // The wildcard filter matches everything.
                     filters = new ScanFilterUtils().createWildcardScanFilters();
                 }
@@ -214,6 +225,14 @@ protected void startScan() {
         }
     }
 
+    @MainThread
+    public void stop() {
+        super.stop();
+        LogManager.d(TAG, "unregistering SamsungScreenOffReceiver as we stop the cycled scanner");
+        // Catch the exception in case it has not been registered
+        try { mContext.getApplicationContext().unregisterReceiver(mSamsungScreenOffReceiver); } catch (IllegalArgumentException e) {}
+    }
+
     @Override
     protected void finishScan() {
         LogManager.d(TAG, "Stopping scan");
@@ -391,4 +410,18 @@ public void onScanFailed(int errorCode) {
         }
         return leScanCallback;
     }
+
+    private BroadcastReceiver mSamsungScreenOffReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            if (!mMainScanCycleActive) {
+                LogManager.d(TAG, "Screen has gone off while outside the main scan cycle on Samsung.  We will do nothing.");
+            }
+            else {
+                LogManager.d(TAG, "Screen has gone off while using a wildcard scan filter on Samsung.  Restarting scanner with non-empty filters.");
+                stopScan();
+                startScan();
+            }
+        }
+    };
 }