Does murderous rage run in the family? Now in its seventh smart and entertaining season, “History Detectives” (8 p.m., PBS, check local listings) examines an angry and threatening letter to President Andrew Jackson, apparently written by famed actor Junius Brutus Booth, the father of John Wilkes Booth, who would go on to assassinate Abraham Lincoln.

For more than a century, Booth biographers, historians and Jackson scholars have dismissed the letter and denied any links to the elder Booth. But a little digging, handwriting analysis and a look at the famous actor’s schedule and correspondence may upset conventional thinking.

Two other items worthy of academic spadework include a sawed-off shotgun believed to have been used during the legendary gangland slaying known as the “St. Valentine’s Day Massacre” of 1929, explored in greater detail on the separate and unrelated program “St. Valentine’s Day Massacre” (9 p.m., History).

There’s also a curious object, thought to be a homemade land mine created in the 19th century to deter grave robbers. While researching the latter, scholars unearth late 19th century advertisements for “graveyard torpedoes” that assure consumers that family members can rest in peace while tomb violators will be blown to pieces. Now that’s something you don’t often read about in the history books.

• Matters of less intellectual rigor but no less passion are examined on “The Great Debate” (9 p.m., VH1), a five-episode series airing over consecutive nights dedicated to some of the big questions of beer-soaked dude-dom, such as “Who’s tougher, Rocky or Rambo? Or what hair band ballad of the Reagan era deserves to be anointed the “most awesome”? Boxing announcer Michael Buffer hosts. To the uninitiated, he is responsible for the catchphrase, “Let’s get ready to rumble.” This will not make for quiet conversation.

• Just wondering out loud: if the host of “Glenn Beck” (4 p.m., Fox News) supports a military coup in Honduras because the deposed president is too much like Castro and Chavez, and then in the next breath compares the duly elected President of the United States to Castro and Chavez, is he still only talking about supporting a coup in Honduras? You do the math.

Words and inferences have meaning and consequences, even when spoken by a self-described “rodeo clown.” How long will Fox News’ corporate sponsors remain deaf and dumb?

Tonight’s other highlights

• A construction fatality sparks an inquest on “Law & Order” (7 p.m., NBC).

• A doctor and patient seem too well-adjusted on “House” (7 p.m., Fox).

• A con man’s partner pays the ultimate price on “Law & Order: Criminal Intent” (8 p.m., NBC).

• A federal judge falls under suspicion on “Lie to Me” (8 p.m., Fox).

• A former gang member’s murder is less than cut-and-dried on “The Closer” (8 p.m., TNT).

• A party proves less than relaxing on “Make It or Break It” (8 p.m., ABC Family)

• “Obsessed” (9 p.m., A&E) profiles a germ-obsessed woman as well as a compulsive hoarder.

Cult choice

TCM reels off four early films starring Meryl Streep, “Manhattan” (7 p.m.); “Kramer vs. Kramer” (9 p.m.); “Sophie’s Choice” (11 p.m.) and “The French Lieutenant’s Woman” (1:45 a.m.).