Series Characters--To Cherish or Not?

One of the problems with a mystery series is that of reintroducing characters. Fans of the series don't want a detailed synopsis of each and every person who appeared in previous books. On the other hand, new readers will be quite bewildered when a person suddenly shows up with a built in role. 

In real life, I feel the same awkwardness when I'm supposed to know someone I've never been introduced to. One situation that was hilariously funny was when one of my daughters was married and no one introduced me to the father of the groom. We were across the room from each other at a party and nodded with weak polite smiles. I would like to think I finally resolved this by simply saying "Hello, I'm Charlotte Hinger. The mother of the woman your son is going to marry."

I probably didn't because I have a real talent for complicating matters. But really, our families would be joined for life. Surely we could do better than identifying one another through the process of elimination.

For once writing a series in first person helps solve this problem, because--as Lottie Albright--and by incorporating the blessed technique of projecting thoughts, Lottie can dread the volcanic disruption of a visit by her husband's daughter Elizabeth, or worry about his daughter, Angie, who falls for cruel men. 

With third person the process is more awkward, plus there is a danger of "spoilers." Revealing plots of previous books. As in, "you know, the evil psychologist we put in prison a couple of years ago." This isn't fair to the new reader who loves book number five, decides to read ALL of the series and discovers he or she already knows how previous books have turned out. 

There are four characters who simply must be in all of my books: the sheriff, Sam Abbot, Lottie's twin sister, Josie Albright, her husband, Keith Fiene, and Tosca, the adorable little Shih-Tzu who somehow wiggles her way into every plot. 

I would love to hear tips and advice from my savvy blogmates on reintroducing all the people we've managed to accumulate through the years.