Summation Gathering: A Subtrope of The Summation, this commonly occurs at the end of a murder mystery.
 
All of the suspects gather together in a room, so that the detective can tell them who the murderer is. The detective goes down the list of suspects one by one, explaining why they are innocent - although some of them may be guilty of other, minor, crimes. Eventually he will get to the guilty party, and explain how and why the murder was committed.
 
Expect at least one embarrassing secret to be unearthed during this scene.
 
Fridge Logic kicks in when you realize that, if the detective already knows who the killer is, he should just have the guy arrested. And it’s probably best to do that by surprise, rather than by giving a long speech in which the list of suspects is gradually shortened and the killer might be tempted to run away before anyone can put him in handcuffs. Additionally any testimony and statements given by anyone present at the summoning would be inadmissible in court, as the those present have been led to believe speculation presented as fact, but the trope works well from a storytelling perspective, since it builds suspense.
 
The Meddling Kids Are Useless: You’re watching your favorite adventure series. A group of plucky kids snoop around the place, get into exciting situations, and even get into danger and need to be rescued. And in the end, a cop arrests the criminal the kids were after. Supposedly, the kids didn’t even help the police at all.
 
Suddenly it dawns on you. The main characters aren’t that useful! They did all the cool stuff (basically, get into all the danger), yet someone else ultimately stopped the bad guy and saved the day. What the heck? Why even bother with these “heroes” and their adventures?
 
Because this is a story where the main attraction, if not the very point, is to watch ordinary people get into all sorts of excitement and danger. Yet they can’t ultimately thwart the villain or solve the problem, because, well, that’s not their job, nor do they have the actual skills for it.
 
This is a way to get kid characters (or average, non-professional adult characters) into an exciting adventure while providing the realism of showing the real police or other professionals doing their jobs and saving the day. Note that despite the title, this doesn’t have to be about young characters specifically; this is about when the main characters, regardless of who they are, are not the ones who save the day (though Character Development does happen). Also note that the full story of the defeat of the bad guy may be available elsewhere, simply not at this particular story we are reading. In that case, the villain was defeated by a Hero of Another Story.
 
See also Little Hero, Big War, which is kind of this on a much larger scale, and with the hero having a larger chance of being the one who actually defeats the villain. Often if the main character pads a lot of the story failing to succeed it’s because We Are “Team Cannon Fodder”.