A few thoughts from a long-time defense attorney:
1. Never hire a hitman. They are always either cops or someone who will use your asking for a murder for hire as a way to lessen their sentence.
2. If you choose to ignore point #1, do not hire someone who is or has been in prison.
3. All jail calls are recorded. No, not all hours are listened to but that really depends upon the arresting agency, the defendant, and the crimes charged. So, some regular joe who gets arrested for felony DUI by state troopers? Odds are nobody is listening to him. Someone arrested by a federal agency for allegedly being involved in a large-scale drug conspiracy? Yeah, the feds listen to all those calls. How do I know? First chance I get, I tell every client facing federal charges that the feds can and will listen to every call. And a couple of months later when the feds produce the calls of my client continuing their drug enterprise, I have to march down to the jail to tell them to
. So even if they aren't lstened to in real time, they are kept and they will be reviewed later.
4. If you want someone dead and you don't want to hire a hitman, that's smart. What's not smart is to the Google 'How to kill someone without leaving a trace'. Don't do that. Even if you're writing a book. Don't do that.
5. If you do decide you want someone dead and that someone works with you, don't drop a note on the table at your job saying, "I quit. Send my last paycheck to [insert address of local jail here]," and then go shoot the person who works with you. Not that I've ever had a case involving anything like that.