One day before the 50th anniversary of the assassination of John F. Kennedy, “JFK: The Lost Tapes” (Discovery at 7 p.m.) airs to offer a gripping and unique insight into what happened that fateful day through newly released government tapes, audio recordings from the Dallas Police Department and testimonies. The film reveals a riveting, behind-the-scenes story of a presidential assassination, a police manhunt for a killer and the vital role news reporters had in keeping the world informed.

Leslie is back to checking off some of her biggest goals for the city council on “Parks and Recreation” (NBC at 8 and 8:30). The first episode in the P&R lineup has Leslie rallying to get fluoride back into Pawnee’s notably unhealthy water. Then, Leslie and Councilman Jamm have a marathon negotiating session, while Ben fills his time between jobs with an odd hobby.

It’s Thanksgiving already on “The Big Bang Theory” (CBS at 8) with Howard’s mother throwing a fit over when he and Bernadette should host dinner for the gang. Sheldon is displeased with the location, and Penny’s past comes back to haunt her.

Francis concerns himself with Mary and Bash’s growing relationship on “Reign” (CW at 9), and reaches out to Olivia for help. Following the threats against Mary, Catherine ensures that the perpetrator will be captured and Kenna finally tells her friends about her affair with Henry.

Olivia’s team is chosen to manage Josie’s campaign in the face of a potential crisis on “Scandal” (ABC at 10), while they’re also still trying to get to the bottom of Operation Remington. After plotting Sally’s downfall, Cyrus fails to consider the collateral damage that could occur as a result.

Election Day arrives and Kristina and Adam remain optimistic on “Parenthood” (NBC at 10). Jasmine and Crosby use the election as a teaching moment for Jabbar, while Sarah helps Hank work through a family issue.

Actors Jonah Hill and Chiwetel Ejiofor join “Late Show With David Letterman” (CBS at 11:35), with a musical performance from J. Roddy Walson & The Business.

Actress Kristen Bell and television host David Gregory are on “The Tonight Show With Jay Leno” (NBC at 11:35), with musical guest Julian Lennon.

Actors Tracy Morgan and Chris Pratt come to “Jimmy Kimmel Live” (ABC at 11:35), along with a musical performance from Pusha T featuring Pharrell Williams.

Rachel Lubitz