I'm an avid fan of horror in general but I also have an interest in true crime. Here is my personal list of favorite YouTube channels from the Horror and True Crime genre. I'll be linking recent videos to their channels or popular ones. I'll briefly add a description of what videos the channel uploads.
5) Gloomy House
Gloomy House is a YouTuber who makes Top 5 videos of mystery or crime. Usually videos tend to be 2-5 minutes and the videos themselves are good despite being short.
4) Cayleigh Elise
Cayleigh Elise is a True Crime and Horror YouTuber that talks about disappearances, unsolved crimes and has a series called Nameless, that talks about unidentified deceased people, usually victims of crimes. She is one of the major female figures in the Horror community.
3) Vintage Files
Vintage Files is a True Crime channel that talks about mysterious disappearance and unsolved crimes. Videos that talk about unknown and not repeated disappearance that is vastly covered.
2) Criminally Listed
Criminally Listed is a channel dedicated to true crime such as murders, disappearances, and mysteries. What I love about this channel is the dedication and research to find crimes that I've never heard about. This has to be my favorite True Crime channel as I always look forward to watching his videos. The videos are long and well done with his narration fitting the video really well.
1) Reignbot
Reignbot is arguably one of the most well known female Horror YouTuber within the Horror community. Reignbot originally started off narrating horror stories before branching off to the True Crime genre. She blew up with her series of "5 things you shouldn't google" and debunking videos from the dark web or mysterious videos.
I hope that you check some of these listed channels that peak your interest.