One case has nothing at all to do with the other. Drawing conclusions is a fallacy. Yes, Chauvin was convicted because he was guilty. Incontrovertibly, irrefutably, scientifically and forensically.
The details in the case you mention:
Russell was driving his 1979 light-blue Chevrolet Malibu and Williams was seated in the passenger seat. A plainclothes police officer spotted Russell's car in an area known for drug deals. The officer checked the license plate which uncovered nothing notable. He then tried to pull the car over for a turn signal violation. Russell did not pull over causing a police chase to ensue. As Russell sped past two officers, they believed that they heard shots being fired. As no firearm was found in the vehicle, the sound was most likely caused by the car backfiring.
Not an execution, but an unwarranted shooting. The first problem lay with the police. The tried and true tactic of having nothing to stop someone on and making something up has caused more problems than you can imagine. And it happens all the live-ling day. That creates officers who walk up to a vehicle looking for trouble.
The couple led police on a 22-minute chase. Not around the block, not for a mile...for the duration of a TV show. Lots of time in there to consider stopping rather than blowing by other police vehicles. No doubt they thought they were going to end up in jail that night. The police officers probably believed the same thing.
The police actions went too far, no question. Do we need to re-imagining policing? No question. But to imply there was no legal blowback is misleading. In May 2014, one of the officers involved, Michael Brelo, was charged with two counts of voluntary manslaughter, but was acquitted. Five police supervisors were also charged with dereliction of duty, a misdemeanor. Their trial was set on July 27, 2015. The families of Russell and Williams filed a lawsuit against the city of Cleveland, and received a settlement of $3 million in November 2014. On January 26, 2016, it was reported that six Cleveland police officers were fired due to their connection with the car chase.
Maybe a verdict like yesterday's will prevent scenes like the one that took WIlliams and Russell.