Former U.S. intelligence officials did forensic examinations of the actual evidence -- the metadata from the “Guccifer 2.0” July 5, 2016 intrusion into the DNC server. Why haven't you heard about it? Because they concluded:
Forensic studies of “Russian hacking” into Democratic National Committee computers last year reveal that on July 5, 2016, data was leaked (not hacked) by a person with physical access to DNC computers, and then doctored to incriminate Russia.
Read their full report here:
https://consortiumnews.com/2017/07/24/intel-vets-challenge-russia-hack-evidence/