Of course, look at the forensic evidence they found against Amanda and then compare with forensic evidence against Raffaele. There is still overwhelming evidence that they were both together, taking circumstantial along with forensic, but I do not know why Raffaele's lawyer didn't try to separate him from the very beginning of the case.
I can only think that they didn't do that based on Raffaele's insistence. Maybe RS thought he better stick with Amanda, or else risk Amanda mid-process revealing his involvement. Then it would be all over for him.
I would think any competent lawyer would have recognized immediately that the best course for him was to separate him from Amanda, since there is more evidence on Amanda.