To pick up about the chapter titles, most of the titles in the third novel are pretty utilitarian ("A Visit to Perry," "Return to U-town," "On the Medical Team"), but some are references to other things.
"Quartet" is the title of Perry Nelson's third novel (as mentioned in A Sane Woman, and probably elsewhere, too).
"Distance and Time" is the title of Perry Nelson's second novel.
"In the Hotel Bar" is utilitarian, but somebody mentioned that it makes him think of butter, so now it makes me think of butter, so it will be changed to something else in rewrites.
"Absolute Beginners" is a song by David Bowie. A terrifically romantic song, chosen for obvious reasons (I'm particularly fond of the version from the "Bowie at the Beeb" CD, by the way).
"A Journey in the Dark" is the name of the chapter in Lord of the Rings where they go through the mines of Moria.
"A Different Choice" is a quote from my favorite Alanis Morissette song, "Out is Through," which is about how to get through problems, you have to solve them, not sidestep them.
"(At This Moment of) The World" has a double meaning, because The World is the name of Perry Nelson's first novel (by the way, imagine calling your first novel The World, especially when you're still a teenager). But the whole title is a quote from a Joni Mitchell song. You can google it if you want, but I won't name the song or the album here (it's the title track), because it would be a big fat spoiler if you haven't read the novel yet.
As for people, I've found that one thing about mystery stories is that you have to create a lot of new characters for each story, and most of them need names. This is a shock for me, since mostly I write about the same characters. New characters are introduced here and there, but usually one at a time.
There is no particular significance to the names of the characters in The Apartment Mystery.
In The School Mystery, which has a lot of suspects, I decided I needed a system, so most of the names of the new characters are from Dark Shadows: Roger, Willy, Amy, James (Jameson), and Carol (Caroline). Some of their physical characteristics and personality traits were shared with the originals, but only up to a point. It was mostly a device to help me keep it all straight. Of course, I avoided having characters named Barnabas, Quentin, and Angelique.
There was a David in Dark Shadows (David Collins, in fact). but the David in the story is quite obviously not based on him. He's based on a friend of mine from high school who was a science fiction enthusiast and who indeed taught some classes at the high school where he was a student.
None of the names in The Hospital Mystery were significant, except that I was inspired by The Dutch Shoe Mystery by Ellery Queen, which took place in a hospital, so I gave the murderer the same name as the killer in that book. Oh, and the gang name "the Scorpions" comes from Dhalgren.
In The Vampire Mystery, most of the new names come from the "Resident Evil" movies: Nikolai, Isaac Ashford, Jillian Wells, Lloyd, Spence, Nurse Betty. If you've seen the movies, you'd probably be able to get some sense of who's more good and who's more evil.
Mindy's name doesn't come from anywhere. Marisa is obviously a reference to Mrs. Coulter (from The Golden Compass), but mostly I just chose it because of the way it contrasted with Mindy. Mindy's home town (Missoula, Montana) was chosen because that's where David Lynch is from, and Mindy seemed a bit like a Lynch heroine (pretty and small-town wholesome, but with darker aspects and depths and possibilities).
Åsa's name didn't come from "Resident Evil," and by the time the story was done, I was certainly tired of typing the HTML code which gives you that little circle on top of the "A."
In the current story, Ron's name isn't a reference to anything. She just barged into my brain one day, announced herself, dropped off some mail, and left.
Stuart Anson, on the other hand, is a deliberate reference to Stuart Rene LaJoie, from the Robert A. Heinlein novel The Moon is a Harsh Mistress ("Anson" was Heinlein's middle name). He's the first elderly character who isn't either a loon (Old Waldo) or a drunken loon (The Professor), and Heinlein novels often included an older character to impart wisdom (Heinlein's wisdom, of course) to the younger protagonist(s). In The Moon is a Harsh Mistress, that character isn't Stuart Rene LaJoie, it's Professor Bernardo de la Paz, the rational anarchist (who is a Loonie, but certainly not a loon). But I used Stu's name because Stu (our Stu) is in an analogous position to the Stu in that book, who was the earth-side ally and representative and agent of the lunar revolutionaries.
As I think of it, Ron was probably inspired by Hazel from the same novel, a young girl who the narrator first sees during a riot, bowling over one of the Authority guards. That seems like something Ron would do.
There will be more new characters introduced in the current story (at least two, since we haven't met either the victim or the killer yet), but I'll give them names when they appear.
Oh, and speaking of names, a reader asked about when Marshall chooses to refer to Jan as "my employer," when he calls her "my wife," and when he uses her name. This was my answer:
Mostly he refers to her as "my employer" or "Jan." The former is used somewhat more often when it's a professional moment, the latter when it's personal. I think in the scenes when they're in bed together, or preparing for bed (or trying to get her out of bed), she's mostly "Jan."
He refers to her as his wife in that one instance (in the last paragraph here) because the thought wouldn't make much sense otherwise. Why would he enjoy taking a brief trip to the city (just the two of them) with his employer? Only because she's also his wife. And remember (though I just thought of this now) these are two people whose life together has mostly been traveling, always just the two of them. Now that they don't get to do it that often, they probably enjoy it even more. Which is probably related to her sudden desire to spend some smooching time with her hubby, though mostly that's because she's in such a good mood in general (with the college thing apparently going to work out).
My idea (at this stage, subject to change) is that the stories are designed to be read in order, so the "big reveal" that they are married is at the end of the first one ("She put her arms around me and we kissed, and I could feel the tears fall from her eyes to my cheeks, and maybe some the other way, too. That's what it's like when you're married to a detective. You sometimes have moments like this on blood-splattered sofas in murder rooms.")
After that, the alert reader should be remembering that they're married, even if I don't refer to it a lot. If someone should forget and then be reminded, all the better, because it makes the point of how complex their relationship is.