Reliable conversation guide for an interrogation game?

[DFlimbingo]

Hello! I'm making a VN right now with investigation elements, similar to Phoenix Wright games when you're asking a character about certain events. My main issue currently is that while Phoenix Wright games are based on evidence (You show a character a certain item, you get certain information from the character's reaction) my game will not feature such a thing and will be more freeform as you get information from dialogue and asking the right questions. This consequentially makes the questions a little too freeform, as I write the questions on the spot using a very vague idea of how the conversation should go.

My question is, in this scenario, what's a good way I can tighten the dialogue into an easier to write and more straightforward method, especially related to the entire conversation's length? It doesn't have to be an actual coded system, more like a general guide about how the investigation would go. I'm currently thinking of an oversimplified number guide where 3 questions would be based on the introduction, 5 would be based on actual questions related to the case, and so on and so forth until the confession. Would this be appropriate, or is something else better suited?

[parttimestorier]

Rather than planning out a set amount of questions, I would probably think about it in terms of what information the answers will give you to unlock more questions. The simplest way to do it would be to have each answer provide sort of a new keyword that gives you another question to ask. For instance, you ask where he was at the time of the murder, and he says he was at the such-and-such bar. So now you can ask who else was at the such-and-such bar who might be able to confirm his alibi, and he says his buddy Bob was there. And now that you have that information, you can say, "Aha! We just talked to your buddy Bob and he said . . ." etc. etc.

The more complex way to do it would be to include some questions that are dead ends, and other ones that might give you a bit of a hint but nothing you can ask directly about yet, until you've also asked a different question that gives another hint and helps you figure it out. I would probably plan this by writing out some kind of chart including all the information you need to learn through the conversation, and plotting out the path(s) you need to take to get there. For example, maybe you arrest a guy who was skulking around the crime scene a few days after a murder looking suspicious, and you start out the conversation with three possible questions to ask:

"What's your name?"
"Where were you at the time of the murder?"
"Why were you skulking around the crime scene looking suspicious just now?"

Ask him his name and he just tells you and doesn't say anything else interesting - that's a dead end. Ask him where he was at the time of the murder, and he just says he was at the such-and-such bar on whatever street and you can go ask the bartender and he'll back him up. That seems like a dead end for now too, because you don't have anything else to say about that. But ask him why he was at the crime scene just now and he says it just happens to be on his way to work. That unlocks some new questions you can ask about where he works and what his schedule is like, and maybe you eventually get him to say something like "I always work the night shift on weekdays." And then you can say "Aha! But the murder was on a Monday night, and you just said you were at the bar! Did you skip work, or are you lying?" And you could have also gotten to that point the other way around, by learning about his work schedule first and then asking where he was at the time of the murder and getting his answer about the bar, which gives the player some more freedom and makes them really feel involved in the conversation.

That's just a random simple example I came up with just now, but I think setting it up that way, thinking about which questions will lead to which information that can unlock more questions, will probably be a lot more interesting than just having a formula of the same amount of questions every time. Hope it helps!

[DFlimbingo]

Thank you for the advice! I'm definitely going to work with the ideas you've brought to the table.