Struggling with a Synopsis

Before I begin writing the story, I write my synopsis. This will act as my writing guideline. See my Feb. 6 blog on the plotting process. With each draft of the synopsis, I add more depth, consistency, and motivation. However, I'm now stuck on two points for my next mystery.

The Crime Scene: My working title is Hanging by a Hair. So I want my victim to be hanged. The problems are two-fold. He's bigger and stronger than the killer. And where in a house can I hang him? I searched through my file of newspaper clippings and came up with one that tells of a woman hanged by a workman on a shower rod. A shower rod? Seems to me it would fall down if the victim is heavy. Where else in a house would this work? And wouldn't the killer have to incapacitate the person first and then string him up? How would this be possible if the victim weighs a lot?

Once I figure out these details, I'll have the killer write a confession scene. Then I will know, before I begin writing, what the outcome is of my story. When I get to the confrontation between killer and sleuth in the book, I'll just slide in this dialogue. My next step is to research on the Internet to see if I can find any relevant news stories that may help spark ideas. If the killer incapacitates the victim first, how is this done? Hitting him on the head is easy, but it's too obvious if you want the hanging to appear as a suicide. Say the killer poisons the vic. What type of poison? How do they get hold of it? Does it act immediately? Does vomiting/diarrhea occur before death, causing a messy scene?

See how you have to think things through. Then the writer has to figure out what clues are left at the scene.     

The Suspects: I'm pretty clear on most of my suspects, having worked through their motives a couple of times and with my critique partners' input. But I am still having one problem. The victim discovers a secret. He tells Suspect A, who tells Suspect B. Meanwhile, the victim also tells Suspect C who pays him to keep quiet. But Suspect C is afraid Suspect A will talk to the authorities. So he threatens her to ensure her silence. Okay, he threatens her with what? What does she want to keep hidden?

She's a professor at a local university. So I've come up with a list of possibilities: Plagiarism? Falsifying credentials? Seducing a younger student? Making up reference material to support a recent publication? Accepting bribes in return for good grades?

Whichever one I choose, how would Suspect C—a real estate developer—find out about it?

I decide Suspect A is a single mother with two college age kids. She needs to keep her job to put them through school. Suspect C threatens her with exposure in a manner that might get her fired. Which one of the above might she have done? Does Suspect C threaten her before or after she tells Suspect B? And why does she tell that person? Because she holds a grudge against the victim, and she knows Suspect C will act on her revelation without getting her involved. So basically, I have to determine what secret she's hiding and how Suspect C finds out about it. Sound complicated? I'm confusing myself by even discussing it here.  

Fortunately, I'm not on deadline, so I can take as long as necessary to work out these points. I'll want my synopsis to read smoothly, follow in a logical manner, and include personal elements in the sleuth's life. In a cozy mystery, the story is more about the sleuth than the victim, the aftermath of murder, and the criminal's psyche, which may be the focus of a serious crime novel. In my stories, the personal relationships among the suspects and how they impact the sleuth are what matter, but still the details have to be accurate and plausible.