The girl is petite. She acts as the decoy, and also messages the pred. She isn't turned off from being touched by the predator, or even kissed. Her main goal is to get the predator comfortable and to trust her so he excitingly drinks her spiked lemonade, which gently sends him off to dream land. But to even get the predator to their home with little to no bread crumbs, she reassures the predator she will ask her mother to pay for an "Uber" under the pretense it's for a friend.

The "Uber" is her male partner: her male partner. His job is to drive the predator to his final destination, circle the block, and dispose of the body after the woman is done killing the pred.

How do they dispose of the body? I'm not sure yet. But I do know this tactic creates a scenario where there are few bread crumbs leading to the couple. It's unlikely the predator tells anyone where he's going. At most, he's meeting a totally legal female friend! Where? Don't worry about it. Usually, it's some loser just sneaking out of the house. Yes, he will be labeled a missing person, but the pred does most of the work for them by making sure his disappearance is done is secret

>>24950326
The duo in your story aren't going to make it very long as serial killers. You're right that are many benefits to targeting child predators, but there are some deep, critical flaws in this strategy.

>>24950337
This is literallyThe Devil All the Time. It's already been written, and it was done very well. The movie was good, too.

>>24950382
FUCK all the good ideas are taken

>>24950367
I have literally never written a story before. The last book I read was in highschool, if you don't count the OPM manga. I was considering this would be a short story, where they would eventually get caught because real justice > vigilantism and all that. What are some flaws you see in the plan? This plan is something I've been thinking about for a long time (except the disposing of the body)

>>24950393
that's the real reason post-modernist literature exists. you can add a bunch of whacky techniques and subplots and make your story-telling seem original

>>24950397
These aren't problems with storytelling or writing, they're logical problems resulting from lack of research and foresight.
There's a lot of ways for poisoning someone to go wrong, and if and when it does, it's going to go very wrong. Relying on lemonade as the only delivery method is a horrible idea. Not everyone will trust you, not everyone is going to want lemonade, not everyone will finish it. They would need something highly toxic and extremely fast acting in very small doses and preferably tasteless. Misjudging someone's weight or metabolic rate, a slow acting agent, something with a foul or distinct taste or odor can all be disastrous. Ideally they would want something common in a household that doesn't require identification or raise any eyebrows at purchase. Poisoning also creates a situation with a lot of evidence to cleanup, they're going to vomit. If you know anything about cleaning fabrics, you know you're only ever cleaning the surface. Incapacitating them with rhohypnol and dispatching them another way would be an altogether better choice, but even that's not foolproof.
What happens when it does go wrong? What happens when they realize they're being poisoned and try to run out onto the lawn or call 911? What's the petit young woman going to do about it with the man circling the block? What happens if the target figures it out and attacks her, or if that's what he came for in the first place? The options aren't great. That's why when you watch To Catch A Predator for example, they are operating in a highly controlled environment. There's a production team and cops in the house and a whole SWAT team outside. They've got one guy driving around. If they have to defend themselves, if they have to stab him or shoot him, then what? They're going to alert the neighbors probably. If they don't they still have a near impossible mess to clean up.
And where is this all happening anyway? Hotels and motels are no good, too many cameras, too many witnesses. An Airbnb that requires a real name and payment information and probably has cameras of its own? Their own house surrounded by nosy neighbors with hd ring cams? Do they keep doing it in the same place, drawing attention to their behaviors? Do they keep moving around, creating patterns for investigators to potentially follow? There's only so far they can travel while maintaining normal lives.
And the whole Uber thing is going to smell fishy to at least some of them. The ones that take the bait are going to be the dumb ones.
You have another very big problem with not knowing who your target is in this scenario. What if they're a cop or someone that can handle themselves? What if they're a judge or politician, someone high profile that's going to be missed? A chatroom screen name doesn't tell them anything, they're not going to give their name out. They won't know who they're dealing with until they're in the car, if they know at all.

>>24950397
>>24950475
These are all serious problems, and it's by no means and exhaustive list, but none of these are the biggest problem.
What happens when they target somebody that's being surveilled by law enforcement or the feds? A local cop or judge is one thing, at least the investigation will be behind them somewhat. But someone that's being actively surveilled? They might move on the meetup. Then they're under a lot of scrutiny, the kind that can request their phone's location data and financial records for the last twelve months.
And that's not even to mention the problem of disposing the bodies.
These can work as plot points, but I would strongly suggest closing the loop on some of them so it doesn't just look sloppy.