Sorry for another silly question so soon. :S
For quick context, the main character (who's thinking the above) and Kyoko both respectively happened upon a murder (so two different cases) perpetrated by what is believed to be a serial killer. Yu is a good friend of the main character. The main character is asking Kyoko about the murder she witnessed (and barely managed to survive) and she's saying that the killer looked just like Yu which the main character refuses to believe, cue the above exposition.
I'm having a hard time pinpointing the exact meaning of とは関係なく here. So the character ponders with the idea that Kyoko's case may have been an isolated incident not connected to the serial murders which is why she managed to survive. Then he entertains the idea that Yu may have been the serial killer.
He says 逆に here but I'm not exactly sure if I'm supposed to read this as（それとも）逆に, contrasting the previous statement（京子の事件は別件なのだろう？それとも僕の事件が別件なのだろう？）or if this is some sort of continuation of the previous statement and I'm interpreting 逆に wrong. If it's contrastive, my next question is redundant.
How am I to understand とは関係なく here? Is it "On the contrary, the case I was involved in doesn't have anything to do with the serial killings and Yu is the serial murder?" or is it "On the contrary, regardless of my case having to do with the serial killings, is Yu the serial killer?" (doesn't make any sense but at this point I'm completely lost on this whole scene anyway).
The way I see it とは関係なく can have two different meanings, "~is unrelated" and "regardless" and I'd lean towards the former translation for the sentence above but as I said, the 逆に is throwing me off here.