Regarding the Anwaltsgeheimnis/lawyer's secret I found this on Wikipedia:
underlined by me
"The lawyer must prevent other persons from gaining knowledge of the relevant information entrusted to him or his employees,
unless the client expressly agrees"
and
"In the German-speaking and English-speaking countries,
the client may in principle waive the lawyer's respect for the lawyer's secret"
Anwaltsgeheimnis – Wikipedia
This sounds to me that FR could instruct his lawyer to share all evidence LE has against him with his wife (or the whole family). I wonder whether this has happened. If it did and the family is still not convinced that he killed her and/or that she is dead the evidence can't be substantial, right?