"I'll Be Gone in the Dark" is the latest true-crime series, but much more. While its six episodes document the hunt for the Golden State Killer, responsible for more than 50 rapes and 12 murders in the 1970s-'80s, Oscar-nominated director Liz Garbus ("What Happened, Miss Simone?") is just as interested in profiling amateur sleuth Michelle McNamara, who helped unmask the criminal before succumbing to an opioid dependency the same day Prince died. There's a lot to unpack, maybe too much. Hit the pause button every 20 minutes to catch your breath.
9 p.m. Sunday, HBO
Top of the world
It seems every adventurer wants to tackle the world's highest mountain -- and every filmmaker wants to record the effort. "Lost on Everest" is better than most, offering a fascinating history lesson about a 1924 trek while capturing the thrills of a recent quest to find the remains of one of those explorers. The film is followed by "Expedition Everest," the equivalent of a scientific textbook, but with prettier pictures.
8 p.m. Tuesday, National Geographic
The great escape
If you're gay in certain parts of Russia, the title of the documentary "Welcome to Chechnya" is ironic. To tell the stories of those persecuted for their sexual orientation, director David France ("How to Survive a Plague") earned the trust of an "underground network" committed to helping the oppressed escape the country. Their efforts aren't always successful.
9 p.m. Tuesday, HBO