I feel like Sarah Lee and the Oaks owner could responsible but would need a proxy to keep their hands clean, using Jake the Snake or the Ravens Coach.
but the offshore account doesn't make sense those bigheads have money. then again it could be a diversion, to make it seem like a small guy, makes me want to say Mark, especially considering the singular blow to the head. but 5 mil...
also why was the coaches letter opener there, had the victim/murderer been in her office? or had the coach been involved in a scuffle? just cause it's there doesn't mean she didn't use a free-weight.
I can't give a verdict but if anyone needs investigating its Sarah Lee, mark and the coach imo. Jake the snake was on the field. If either the coach or ravens owner were aware of the possible black mailing b/w Mark and victim .... then he could have been coerced.
5 mil though, gf rachel may have known about his wealth, and the best friend mark could have been cued into this during the affair, maybe the both of them planned to escape the country or just the gf. Victim has a lot of possible enemies lol. I want to say Rachel too but she was in the box. Emma is in debt and an embezzler. if others know of her embezling and debt, the letter opener may have been planted and money extracted for more diversion. More evidence needed imo to get anywhere...
Mark has no loyalty it seems he's black mailing his gf and best friend, etc. no mention of the secret mark was being blackmailed for.
I want to say mark he's just the perfect scape goat. For the sake of this contest though, I'm going to say
Emma was the henchman

irl, i'd be really pissed off about having to make a verdict with the limited evidence, but Mark would likely be gettin canned.