"Cohen said he also established a shared bank account, putting up $10,000 for materials.
But the money started to disappear, and the projects rarely came to completion.
“He wouldn’t do the work. He wouldn’t fill the orders. … It was always excuses, ‘the sun’s in my eyes,’” Cohen said.
By August 2013, Cohen had enough of a man he said he came to completely distrust. He ended their business dealings."
This ^^ part shows the same pattern that the State describes, that created conflict between him and Joey.
“I commissioned a few steel sculptures from Charles,” Adepoju said. “Next thing I know, I was his piggy-bank and he owed me over $4,000. I’m glad that we did not follow though with the registration of our business.“
Despite Merritt referring to Adepoju’s Hesperia office as “his office,” Adepoju said the cowboy hat-wearing metal worker only came Adepoju’s office when he needed money. After Adepoju discovered Merritt’s “shady background,” he quickly cut ties with him and took him to court to get his money."
Again, that ^^^^ is the same pattern. Chase makes promises that he does not keep, and begins taking Money that he cannot or does not pay back.
The above info does not 'prove' that Chase killed the McStay family. But it does show a likely motive and an explanation for the discord and animosity that permeated their business relationship at the end.