Responses
The ghosts did follow that serial killer but thats just it. They cant do anything. Its why they brought the mc so whenever something comes up, they can file the report. But i think they already tried with giving reports to the cops when the orphan friend ghost was still on serve as cop.
i think it's safer for the ghosts to follow the killer alone instead of letting MC tag along with them. the killer won't see the ghosts, but he'll definitely notice that MC is spying on him and that would be more dangerous. they can report back to MC after seeing any evidence or progress and MC can just tip off the police anonymously..