I hate this BS to be honest, but I compared the handwriting on this letter to two different letters that we know he wrote. in the picture you see consistent letter patterns. I did this same analysis with the holli letter and determined it was real back when the horde attacked her. People need to focus less on fanmail and more on the cause.

for context:

https://www.reddit.com/r/BrianThompsonMurder/comments/1jcuxpv/lm_responds_to_someone_who_sent_him_their/

https://www.reddit.com/r/BrianThompsonMurder/comments/1jd2kud/subscribed_substack_letter_interpretations/