A Shade of Gray - Season 4 - Episode 21 

When profiling a series of child abductions and murders, the team discovers that one of the cases may not be the handiwork of the serial killer they apprehended.
মূলশব্দ: season 4, full episode, episode 21, ক্রিমিনাল মাইন্ডস্‌, a shade of gray