“Radiolab” researcher Latin Nasser tries making his own discoveries on the new series “Connected” (Netflix, streaming) drawing broader associations between seemingly desperate elements in the most entertaining way possible. 

A pair of well done and engrossing true crime documentary series end their stories tonight. “I’ll Be Gone in the Dark” (HBO, 10 p.m.) wraps up with the arrest of an elderly former police officer charged with rapes and murders from decades earlier. 

Also concluding is the five episode “Outcry” (Showtime, 10 p.m.) and the fate of a high school football star convicted of child abuse. 

The new series “Britannia” (Epix, 9 p.m.) returns to the time when Druids and the Rome fought over what’s now England. 

In the imported “Taskmaster” (CW, 9 p.m.) is a British comedy game show in which contestants (who are usually UK comics) have to do some unusual feat. Greg Davies hosts. 

The astronauts who went up to the International Space Station from a Space X ship two months ago return this afternoon and can be seen in “Space Launch Live: Splashdown” (Discover, Science, 1 p.m.).