Was there an early preview of Kagamigami or a similar series in Shonen Jump? Alright, so this is driving me crazy but I recently read the first issue of Kagamigami that came out in Shonen Jump (I'm a few weeks behind). I remember reading another manga that felt almost the exact same as Kagamigami. In the manga I read, the crime takes place in a tunnel, not in front of stairs like in the recent issue. The evil Shikigami also wasn't called the "Ripper" I believe, and the main character didn't have a detailed discussion with the culprit like she does in this one.

The premise is almost the exact same: girl with power to trace objects becomes detective. The Shikigami that the boy uses are almost the exact same as the manga I remember reading. Besides re-downloading every issue of Shonen Jump, does anyone have an idea of what this might have been?
I suspect you may have read Shikigami Twilight Days (式神トワイライトデイズ), published in 2014 vol. 28, which is the one-shot predecessor to Kagamigami.



In case you're interested, I found this by using this nifty Shounen Jump database and searching for the author (Iwashiro Toshiaki / 岩代俊明) in the oneshots (読み切り) section at the bottom.

Kagamigami's dic.pixiv page verifies that Shikigami Twilight Days was the one-shot version of Kagamigami.