Just how far can we go to help another human being? And just how close can a filmmaker get to his subject? These are just two of the questions posed by the documentary “Stevie” (6:30 p.m., Cinemax).

When filmmaker Steve James attended Southern Illinois University, he became a Big Brother to Stevie, a troubled boy from the countryside. In the years to come, James won acclaim and an Oscar nomination for his debut film “Hoop Dreams.” But he still wondered whatever happened to his little Brother.

Shot over four years from 1995 to 1999, “Stevie” follows the two men’s painful reunion. James discovered that Stevie’s troubles had only multiplied since childhood, including several stints in jail for passing bad checks, petty theft and violent behavior. “Stevie” introduces viewers to Stevie’s turbulent past, his emotional and physical abuse, his time in several institutions and his enduring relationships with his sister and stepgrandmother.

When Stevie is accused of molesting his niece, it forces the filmmaker and others to re-evaluate their perceptions of the troubled subject.

• Tomorrow night, UPN will broadcast “Amish in the City,” a reality series based on the 2002 documentary “Devil’s Playground” (8 p.m., Trio).

The film focuses on the Amish practice of “rumspringa,” which roughly translates as “running around.” Amish encourage their teenagers to leave their sheltered world and experience the pleasures and temptations of the “English” world, or modern society. They hope that the teens will return to the fold after rumspringa, ready to settle down, marry, raise children and embrace the faith.

Tonight’s other highlights

• Mrs. Nakumura and Mrs. Biggins announce their allotments on “Trading Spouses” (7 p.m., Fox).
• A shopping-mall freak-out on “Gilmore Girls” (7 p.m., WB).
• Jim Lehrer anchors three hours of Democratic National Convention (7 p.m., PBS) coverage.
• Breathless globetrotting on “Amazing Race 5” (9 p.m., CBS).
• Two college pals go out partying, and one does not survive the evening on “NYPD 24/7” (9 p.m., ABC).
• An angry patient returns after a liposuction goes poorly on “Nip/Tuck” (9 p.m., FX).

Late night

John McEnroe and Zach Braff appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno welcomes Tom Arnold on “The Tonight Show” (10:35 p.m., NBC) … Julie Delpy appears on “Jimmy Kimmel Live” (11:05 p.m., ABC).

Tina Fey, Jamie Foxx and John Mayer are booked on “Late Night with Conan O’Brien” (11:35 p.m., NBC). Beth Ostrosky and Polyphonic Spree are scheduled on “The Late, Late Show with Craig Kilborn” (11:37 p.m., CBS).