To begin with, the show has an undeniable “ick” factor. The men (and to date they are all men) are mostly losers who show up packing booze and condoms. It is also undeniably compelling television. Each show follows a similar pattern: after asking the mark to come in, the decoy disappears to change clothes or go to the bathroom. Then, in a startling switcheroo, Hansen appears from off-stage and directs the man to take a seat. The men almost always comply, concluding that Hansen is either a cop or a father. The marks then proffer comical denials about what they are doing at the house, which never include their intent to have sex with a minor. Hansen then produces some particularly salacious details from their Internet chat with the decoy (“But you said you couldn’t wait to pour chocolate syrup all over her and lick it off with your tongue”). The mark then switches gears to say he has never done anything like this before and was just kidding around or role playing, which in turn cues Hansen to say something like, “Well, you’re playing on a big stage, because I’m Chris Hansen from Dateline NBC,” at which point cameras enter from off stage like furies summoned from hell. The mark, now fully perceiving his ruin, usually excuses himself, often pausing to shake hands with Hansen — the cult of celebrity apparently transcends even this awful reality — then exits into the waiting arms of police outside who swarm him as if he had just shot the president.

The police busts are the emotional capper to the encounter, one that highlights the show’s uncomfortably close affiliation with law enforcement. On the first two “Predator” stings, the show didn’t involve arrests, an omission that garnered complaints from viewers and cops alike. Though certain individuals from the initial episodes were subsequently prosecuted, the lack of police involvement from the outset made it hard to make cases that would stick. “The number one complaint from viewers was that we let them walk out,” says Keller. Starting with the third show and in the five subsequent stings, police were waiting to take down the suspects. In our interview and in his congressional testimony, Hansen is careful to refer to those arrests as “parallel” police investigations, as if they just happened to be running down the same track as Dateline, but the close cooperation is always evident. At a time when reporters are struggling to keep law enforcement from encroaching on newsgathering, Dateline, which is part of NBC’s news division, is inviting them in the front door — literally. Hansen tried to deflect this criticism of the show by saying that the volunteers from Perverted Justice serve as a “Chinese wall” between the news people at Dateline and the police.

But as we’ve learned from recent corporate scandals, such Chinese walls are often made of pretty thin tissue. In the case of “To Catch a Predator,” Perverted Justice does most of the groundwork preparing the shows and roping in the men. Initially, Dateline’s responsibility was to cover the group’s expenses, procure the house and outfit it with hidden cameras and, of course, supply Chris Hansen and airtime. However, after the third successful “Predator” show, Perverted Justice hired an agent and auctioned its services to several networks. NBC ended up retaining the group for a fee reported in The Washington Post and elsewhere to be between $100,000 and $150,000. Hansen would not confirm an amount but said he saw nothing wrong with compensating the group for its services, likening it to the way the news division will sometimes keep a retired general or FBI agent on retainer. “In the end I get paid, the producers get paid, the camera guy, why shouldn’t they?” says Hansen.

Douglas McCollam is a contributing editor to CJR.