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?