A couple weeks ago I was watching an episode of Forensic Files on Netflix, when a specific grammatical technique (I honestly don't know what else to call it) was mentioned. The name fails me, but I remember it was something like "Ironic Something-ism".
The best example that comes to mind was a quote from a note left by a murderer:
"She wanted to cut it off, so I cut off her head."
The term specifically had to do with using the same word twice with different meanings as in the quote. What is this called? I've tried Googling it, but I can't find anything. I might go back to the episode later, but I'm currently on lunch break at work and it's driving me insane.