Detective E. Mueller (2021)

Detective Eric Mueller just solved his first case of the new year. He's just about to go home when an old acquaintance shows up at his door. She tells him that her sister has gone missing. Eric makes it clear that he doesn't care about this while he still wants to know what's going on. He investigates and discovers that it is more complicated than it seems. Out of all the suspects, one must have done it or several?