More properly, Czarist methodology. Back in the day, one of the Czars had a royal garden to supply fresh produce to the palace, including cabbages. He reputedly appointed several of the cabbages to his cabinet. When policy didn't work out, he would publicly announce that several members of his cabinet had been beheaded for their incompetence. This worked as long as no one asked which ministers had been executed or demanded to see the heads on pikes at the palace gates.
The technique survives today although with a bothersome press on the loose, a scapegoat must be named and publicly shamed or fired. Since the Freddie Gray case in Baltimore, the mayor has had to walk a PC tightrope between reducing the police presence while at the same time, reducing an unacceptably high crime rate. Naming a "kinder, gentler" police commissioner seemed like a good start and the usual suspects acclaimed the reduced enthusiasm of the cops on the streets.
The reduced enthusiasm was probably more a reaction of the street cops to the well founded feeling that upper management no longer had their backs, thus arrests went down and crime went up. Last year set a record for murders in Baltimore. The mayor has risen to the occasion and fired the police commissioner, arguably for doing exactly as he was told.
This bodes poorly for his replacement who would take the job knowing that he needs to do what the boss wants or get fired. The boss wants both less crime and fewer arrests. Sucks to be commissioner in Baltimore.