Deleting crime after scrolling with ViewPager is not immediately reflected on the CrimeListFragment

Android Programming (3rd Edition) 13. The Toolbar
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  1. Someone talked about it in next Chapter. Deleting Crime deletes the Crime from the DB but throws IndexOutOfBoundsException

  2. For this case, it works for me to change mCrimes = new ArrayList<>(); to mCrimes = new CopyOnWriteArrayList<>(); in CrimeLab.java.

How can I got it? Just basing on the output of the Logcat: java.util.ConcurrentModificationException,
I searched remove Fragment Page from ViewPager in Android java.util.ConcurrentModificationException, and find https://stackoverflow.com/questions/6621991/how-to-handle-concurrentmodificationexception-in-android