‘N Sync’s Chris Kirkpatrick and pop star Willa Ford co-host “Miss Teen USA 2002” (8 p.m., CBS). And I thought the boy band thing was over. Fifty-one young women will compete for the teen tiara in the resort town of South Padre Island, Tex. Each contestant will be judged in three categories, including swimsuit, evening gown and interview. Teens have so many opportunities to wear evening gowns these days. Kirkpatrick and Ford will be joined by hip-hop singer Bow Wow, who appeared in the summer movie “Like Mike.” Somewhere along the line, Mr. Wow shed his “‘Lil.” Last year’s winner, Marissa Whitley, Miss Teen USA 2001, will crown her successor at the conclusion of the two-hour primetime broadcast. Tears will flow.

As all “CSI” fans know, forensic science has given detectives a great new tool for catching elusive bad guys. But hard work and luck are still key ingredients to good police work. “The Disappearance of Dawn” on “The System” (9 p.m., Court TV) chronicles an amazing three-decade search for the man who raped and killed young mother Dawn Magyar in 1973. The case remained unsolved for years, until teen-age boys discovered the abandoned murder weapon while swimming not far from the murder site. Police used the pistol’s serial number to track down its owner. He, in turn, led them to a suspect who could be linked to the victim only by DNA evidence, using technology that had been developed decades after Dawn’s death. A compelling account of detectives who simply would not let go.

“Junkyard Wars” (8 p.m., TLC) enters a new season with a challenge to two teams of gear-heads to build “Manic Mud Racers.” The Model-T’s assemble their hot rod from an existing four-wheel drive vehicle but add their own crazy variations. The Detroit Muscle team assembles a vehicle from scratch, scrounging an engine, drive train and a complex hydraulic steering mechanism from the scrap heap.

Tonight’s other highlights

A high school football star (Riley Smith) has to choose between the party life and a scholarship in the 2001 comedy “Full Ride” (7 p.m., WB).

C.J. grows increasingly fond of her security detail (Mark Harmon) on a repeat of “The West Wing” (8 p.m., NBC).

Bernie takes the kids to his old comedy clubs on “Bernie Mac” (8 p.m., Fox).

Catch all six episodes of the 1989 BBC series “Traffik” (8 p.m., Sundance) that inspired the 2000 movie drama “Traffic.”

Three minus one equals two remaining finalists on “American Idol” (8:30 p.m., Fox).

A 7-day-old infant goes under the knife on “ICU: Arkansas Children’s Hospital” (9 p.m., ABC).

Gwyneth Paltrow discusses her Oscar, her movies and her love life on “Revealed” (9 p.m., E!).

Series notes

“Brother” is new … Stuck inside on “Big Brother 3” (7 p.m., CBS) … Brooke Burns hosts “Dog Eat Dog” (7 p.m., NBC) … Amateur acts on “30 Seconds to Fame” (7 p.m., and 7:30 p.m., Fox) … A night out at a Japanese restaurant on a one-hour episode of “My Wife and Kids” (7 p.m., ABC) … On back-to-back episodes of “Enterprise” (UPN), a diplomatic crisis (7 p.m.), alien hospitality (8 p.m.).

On back-to-back episodes of “The Drew Carey Show” (ABC), the store goes belly-up (8 p.m.), Drew hires his brother (8:30 p.m.) … A murder may be linked to a Little League scandal on a repeat of “Law & Order” (9 p.m., NBC).

Late night

John Travolta and Nelly appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno hosts Mike Myers and Jewel on a rerun of “The Tonight Show” (10:35 p.m., NBC ) Steve Irwin and Amy Sedaris are scheduled on a rerun “Late Night with Conan O’Brien” (10:35 a.m., NBC).