Yes, an autopsy report found no gunpowder, per the following from the link.
" .... But an autopsy report found no gunpowder on Brown’s body, suggesting he was killed at a distance.That autopsy report, performed at the request of the Brown family by Dr. Michael Baden, a New York forensic pathologist,....". bbm ubm
That autopsy was the second autopsy, and Dr B ack'ed that he did not have access to MB's clothing.
Dr Case, the StL Co ME, a forensic pathologist, did have access to MB's clothing.
Others here pointed out that MB's body would have bn washed/cleansed/(term?) --
-after the first autopsy, and
-(after embalming), and
-before the second autopsy.
So 2nd autopsy would not have found gunpowder that the 1st autopsy would have found.
JMO IMO MOO
RIP MB