As it turns out, many theories were wrong.
The murderer was a local Philadelphia white guy named Jason Smith who was an exterminator she hired, and she apparently had a dispute with him over the work.
She did not know this guy and his motive was apparently not robbery.
His story is that she insulted him during their argument, he lost his cool and hit her, she fell and hit her head and then he got scared and tried to hide the evidence by trussing her and burning the place.
Which is probably exactly what his attorney told him to say.