1) “Saturday Night Live,” 11:29 p.m., NBC. John Mulaney (shown here was an “SNL” writer for five years, best-known for molding Bill Hader’s hilarious Stefon. He returned when Bill Hader hosted, to write more Stefon. Mulaney’s been busy lately with everything from acting to stand-up to (for a year) his own situation comedy. Here’s a rerun of his second turn as host, with Thomas Rhett as music guest.
2) “Witness to Murder: A Darrow & Darrow Mystery,” 9-11 p.m., Hallmark Movies & Mysteries. The Hallmark channels like to plug likable actresses into a string of movies. So Kellie Martin’s “Mystery Woman” films are from 9 a.m. to 9 p.m., followed by Kimberly Williams-Paisley. She plays a lawyer, working with her mom (Wendie Malick); “Witness” — which debuted Sunday on the separate Hallmark Channel — has a smart plot, lame scenes at home, but good ones with the prosecutor (Tom Cavanagh).
3) “NCIS,” 8 p.m., CBS. When a Navy lieutenant is killed in his hot tub, the team ponders his odd neighborhood. Also in this rerun, Torres faces trouble after a volatile night with Jimmy Palmer.
4) “America’s Got Talent,” 8 p.m., NBC. The show finally has its 10 finalists, ready to perform Tuesday and to have a winner on Wednesday. Here’s a rerun from the semi-finals.
5) “The Mule” (2018), 6 p.m., HBO. In real life, Leo Sharp was a World War II veteran and a horticulturist, highly respected by daylilly enthusiasts. He was also arrested at 87 for being a drug courier. That story was strong enough for Clint Eastwood to take his first acting role in six years. Eastwood also directed, making a slow, low-key film that is charming mainly because it’s true.