The old adage about storytelling, so pervasive it’s basically a cliché, is “show don’t tell”. (So shouldn’t the word be “storyshowing”?) The idea is that the crafter of the story should not bluntly state or tell the themes and ideas of their work. Rather, they should present or show things happening that lead the viewer organically to the themes and ideas.
Over three 40-ish minute episodes, “Mastermind: To Think Like a Killer” does nothing but tell, tell, tell. A necessary evil of the true crime docuseries form, so often marked by talking heads and case files and the like? To an extent, but superior versions of this type of series use a keener sense of “telling” to reveal and deepen.