What drives a man to mass murder? “Norway Massacre: The Killer’s Mind” (8 p.m., Discovery) examines the motivations of Anders Behring Breivik, the alleged killer who terrorized Norway with a bombing in downtown Oslo and a shooting at a summer camp. This one-day rampage left more than 70 dead and devastated Norway’s national psyche.

“The Killer’s Mind” interviews leading experts on criminal psychology, including professor David Wilson and Johns Hopkins University’s Katherine Newman, who offer theories about what led to the carnage.

While many school shootings have been characterized as the works of deranged loners, the Norway shootings are steeped in ugly politics. Like Oklahoma City bomber Timothy McVeigh, Breivik submerged himself in fringe, paranoid theories and seemed particularly affected by websites — many from the United States — fanning anti-Muslim paranoia and warning of a looming war between the “Christian” West and Islam.

While the attacks in Oklahoma City were universally condemned, the Norway mass homicide has inspired a very different response from some on the fringes, particularly in the United States. Far-right American columnist, presidential candidate and frequent MSNBC contributor Pat Buchanan has gone so far as to write that “Breivik may be right.”

• Inspired by comic books and their movie adaptations, more than 300 Americans have decided to don costumes and fight crime on their own. The documentary “Superheroes” (8 p.m., HBO) follows these real-life heroes on foot patrols in cities across the country, from Brooklyn’s anti-crime league The New York Initiative to San Diego’s lone masked man, Mr. Xtreme.

• The stars of UPN’s “Sister, Sister” return with “Tia & Tamera” (8 p.m., Style), following the celebrity twins as they embark on marriage and motherhood.

• Patricia Heaton hosts “The Gracies” (6 p.m., Hallmark) honoring programming created by women for women.

Tonight’s other highlights

• The chef pits red against blue on “Hell’s Kitchen” (7 p.m., Fox).

• A new season of “Bachelor Pad” (7 p.m., ABC) begins. If you’ve seen one mansion, you’ve seen ’em all.

• Omega girls on “Eureka” (7 p.m., Syfy).

• The top six compete on “MasterChef” (8 p.m., Fox).

• The countdown begins on “Warehouse 13” (8 p.m., Syfy).

• A scandal-plagued minister is slain on “The Closer” (8 p.m., TNT).

• “Anthony Bourdain: No Reservations” (8 p.m., Travel) explores the cuisine of California’s High Desert.

• Lindsay Wagner guest-stars on “Alphas” (9 p.m., Syfy).

• “Unsung” (9 p.m., TV One) profiles DeBarge.

Cult choice

• TCM offers 24 hours of films featuring Orson Welles, including “Citizen Kane” (9 p.m., TCM), of course. But there’s also “The Immortal Story” (3:15 a.m. Tuesday), a rarely shown effort Welles made for French television in 1968, starring Welles and actress Jeanne Moreau.