The police haven't found it out yet. They started with the letters and spoke to everyone connected to Louise. But what Johanna was confused about is why Bonnie didn't get any scratch? Or maybe they went directly to Louise to kill her, but how did they know which room she was in before rummaging through every room? Something was off as she asked the police what they found. She was eager to find the killer, but it seemed that her boss knew who it was. The police even suspected her boss but it's impossible since she's the kindest person she knows.
"I would like to request footage of every interrogation," Johanna asked the chief. The assistant police chief hesitated for a while but then he spoke to the investigator and convinced him. Once she had it, she was escorted by three bodyguards to Keira's penthouse.