Psychopathy is a subject I've grown increasingly interested in the past few years. Here are a few videos I found very informative.
Here's an excellent, relatively short video from David Whitehead of the Unslaved podcast with a few key points on how to identify a psychopath:
Here's a full playlist with hours and hours of content about psychopathy from Thomas Sheridan. The content begins at about the 4:40 mark in this video:
Lastly, here's an hour and a half long presentation from Jake Morphonios on the psychopaths in the higher echelons of business and politics. Unfortunately he no longer has this video on his actual channel, likely due to the heavy YouTube censorship. At least it's still available to watch from a mirror: