Over at the Horn Book blog Roger picked up on my complaint about the lack of YA mysteries and chimed in with his own thoughts on why there aren't that many out there. Lots of folks have something to say in the comments but one thread that seems to be coming through is that it is hard to write a realistic teen mystery. The thought is that in adult mysteries the protagonist is often a PI or cop and that explains why they often find themselves solving a crime. (I don't know if I completely buy this - there are mystery series built around characters who are caterers, antique shop owners and dog walkers, so it seems like you can just suddenly bump into a body time and again for no reason.) I do agree that it is not so easy to explain a teenager's involvement in a violent crime however - you can certainly do it for a single book but sustaining a series would be more difficult. I've been thinking about it though, and I've come up with a few plots that would easily allow for a recurring teen detective set in the contemporary world (no wolves, vampires, or alternate history scenarios needed.)

1. Gangs. Urban gangs are full of teenagers, so basing a series on a teen that goes undercover into a street gang to help police stop the flow of guns and violence in his neighborhood would be easy to construct. You could give him a back story based on the loss of a sibling/friend/etc. to gang violence to explain why he gets involved. There are endless possibilities here for crimes to solve and the rising tension of whether or not he will be exposed as a "double agent".

2. New Orleans. The more I think about it, the more I'm certain there is great potential for a mystery series set in NOLA. The city makes an excellent backdrop and the state's long history of political corruption, which has become even more exposed since Katrina, provides all sorts of opportunities for crime solving. In this case you again could focus on teens trying to save their neighborhood (the Lower Ninth Ward comes to mind simply because it is very nearly infamous at this point) and you could have them focus on Katrina crime (exposing covered up crimes that occurred during the storm, or environmental crimes since the storm, or political corruption in relation to the rebuild effort).

3. Freeing people convicted of crimes they did not commit. Northwestern Univ and the Innocence Project has become sort of ground zero for the efforts to overturn death row inmate convictions and it has become abundantly clear that a lot of people get thrown in jail because they don't have enough money for a decent defense. You could have a group of kids who come together because they are all present at a party/sporting event/whatever where one teen gets accused of a crime he did not commit. He gets thrown in jail and everyone's screaming for him to be tried as an adult. The adults think they know best and the teens go to work to expose the truth. When they reveal the true nature of the crime they decide to continue doing the work for other teens who get in trouble. (You could make one of the kids the child of a lawyer which would make it easier to get access to some info.)

4. Environmental crimes. The environment is going to be a topic in the national conversation for the rest of our lives so having a group of kids who uncover eco-crimes and bring polluters/habitat destroyers/corrupt politicians to justice would be easily marketable. I've seen this sort of thing for younger kids but if you increase the violence and make the crimes more dangerous, you could easily insert enough tension to get older kids involved. One of the things that first attracted me to the Travis Magee series was the way Travis was often involved in schemes in Florida that would harm the environment. (John D. Macdonald was WAY ahead of his time.) Set it in Florida or anywhere along the Gulf Coast (LA would work great) and you could run with this for ages.

5. Native American/Alaskan crime. I was thinking about this for Alaska at first because suicide is a huge problem among Native Alaskan teens. A Native kid who shows up dead can be easily dismissed as a suicide. His/her friends think that's wrong but no one believes them. They find out the dead kid saw something/knew something he shouldn't have and was killed to be silenced. In AK you could run with someone bootlegging liquor in a dry village, or selling drugs, or setting fires, or stealing or on and on and on. In the Lower 48 you could angle it more towards the BIA and corrupt political practices that continue to keep money out of Native American hands. There's a lot you could work with here and I'd love to see a mystery series with Native teens as the heroes.

So there you go - five plots off the top of my head all of which could work for a YA mystery series. I know these are only the most basic of story ideas but still - they are possible. Personally I'm working on a memoir about Alaska flying, an essay about the myths from the John Franklin Northwest Passage expedition and a YA story about a girl, Joan of Arc, a ghost of WWI and an old family secret. No mystery writing for me in the near future but for someone, I hope there is - I know I'd like to read what you've got.