And yet DK wasn’t the one cashing forged checks or ringing up Quick books trying to cover his tracks was he?
And Joey forgave DK ( which personally I don’t understand) but he did seemingly.
This whole angle of DK is such red herring! DK was a guy who fought with Joey over the website. It's such a common thing, this adversarial relationship between optimizer and client. DK seems to be rash at times, hence the "threat". However, I think even Joey didn't take it seriously -literally- since he "forgave" him. He just decided to get more control over his business and to buy DK out as a way of doing that.
The only things I can find that would have pointed to DK as a suspect were that "fight", and now there's a girlfriend who says he confessed. Yet, Joey still did work -for a long time- with him after the "fight", and there are girlfriends all over the place who have complaints about DK. Apparently, he wasn't very a very good boyfriend. In this context, the "confession" seems highly suspect.
CM is the only one for whom there is a long and connected narrative of history, relationship, disparaging comments, lies and changing of stories, omissions, pings, forged checks, DNA, bodies buried in his own stomping grounds, trucks on video looking an awful lot like his own, etc., etc., etc.
All of these things fit with Chase, not DK. Chase was known to have the physical fitness, the familiarity with the high desert, history of digging in the high desert, and with proven lack of major boundaries -a criminal. And, despite being a "very-involved father", apparently was terrible at supporting them, being there for them (how are you there for your family when in prison) etc. He smears his dead "best friend's" wife in public. An all around lousy guy.
The only thing I can say about DK is that he can be assured that, despite being the constant target of smears by the defense team, at least he doesn't have to worry about being convicted of murdering the McStay family.