IF "snitching" was THE reason for LB's death/murder, I have someone in mind, who could have organized it. We heard, that Liz cared for their household budget and didn't shy away from speaking out her anger, when SB's checks bounced. Maybe, she knew about some crooked things in this part of the building industry and threatened to use her knowledge in the future. In addition, she knew about certain private things, which may have played an important role re. "money" and maybe, Liz threw everything into one pot (for me very understandable!), when desperate about their (LB's and SB's) unregulated income.
Perhaps "snitching" wasn't done already, but someone (a Macho anyway) had fear, it would happen in the near future. When the killer didn't look like someone of a certain race, it may have been a special clever move, well thought out. Wearing a flowing angel's robe and very blonde curls would have made a nice disguise. - All moo.