WARNING: The following contains spoilers for the Chapter 1: gaze, of i tell c by Kazusa Inaoka, David Evelyn and Sara Linsley, available in English now from Viz Media.
Shonen Jump's latest mystery series, i tell c, puts an unusual spin on the game of cops and murderers by, as the characters put it, "fighting poison with poison." Namely, the main protagonist, Detective Risa Aioi is far creepier, scarier and more unsettling than almost any murderer.
With only one chapter released so far, the manga wastes no time introducing Sakon and his greenhorn brother, Ukon Futatsuki, who are normal detectives that appear to be Aioi's watchdogs, hot on the trail of a stalker-turned-murderer. The manga quickly sets up its first fake-out, showing the suspect, Tagame, repeatedly encountering a woman whose face is shrouded in darkness and whose sudden appearances and disappearances may easily lead the reader to believe that she is the killer, finding a new target -- but that's not quite the case. In fact, this shadowy figure is Dectective Aioi.
Rather than hunting down clues, Aioi has an innate sense of who the killer is, causing her to immediately fall in love with them. While she proves herself more than capable of finding and following evidence to reinforce her love, noting things like the scent of a certain shampoo and receipt doctoring, that's secondary to her ultimate goal of running away with a criminal.
While Sakon and Ukon discuss her straight-up illegal and stalker-y behavior (breaking into suspects' apartments while they sleep, finding and obtaining their phone numbers, and going through their emails without a warrant or permission), they have to admit that her methods work -- and that the reason the upper brass allows it is simple: while Aioi is highly unlikely to arrest the preparator (due to her affection for them) -- it's equally unlikely that any criminal would willingly join her. Simply put, she out-stalkers the stalkers.
As a result of her unorthodox methods, any criminal she falls for often gives a full confession and wants to go to prison to get away from her. But this is no simple act to creep out the criminals, or the beginnings of a good-cop, bad-cop routine with her partners -- her love is completely genuine. As Ukon explains to Sakon, Aioi was the victim of a kidnapping case and ended up falling in love with her kidnapper -- an almost textbook case of Stockholm Syndrome, save for the fact that she appears to hold no resentment towards the police for apprehending the criminals she loves (though she would certainly prefer that they hadn't).
Part of her reasoning for this may be explained in her answer to Sakon when he asks her why she allows herself to fall in love with lawbreakers -- she wants to love them before the weight of what they've done crushes them. In some ways, this indicates that Aioi feels she could possibly change them for the better or at least comfort them before the reality of what they've done hits, and she wants to help them with that guilt and pain.
Either way, the wide and near unpredictable range of behavior Aioi exhibits throughout the chapter, from what could be described as "a middle-schooler with a crush" to an outright stalker to near yandere to quiet mild-mannered girl drinking tea in her own personal room in the precinct. It leaves the reader with a deep sense of justified fear and discomfort. This is a woman who can do anything, and it wouldn't be out of character. While Aioi will likely continue to use her illegal methods to find killers rather than become one, that doesn't put it out of the question.