Laplace's Witch

An environmental analyst is asked by the police to determine if two deaths by hydrogen sulfide poisoning are an accident - or a murder. But when he meets a young woman at both sites, a scientific mystery begins.
(Source: IMDb)
~~Adapted from the novel "Rapurasu no Majo" (ラプラスの魔女) by Higashino Keigo (東野 圭吾).