There of course is also an effect where people think all of Portland is on fire because they saw a protest on TV once. But also Portland has had twice as much gun violence this year than all of 2020, which seems like a problem someone should do something about.

But yes, before that it was limited to a few hotspots like St Louis which still had environmental lead problems. Meanwhile DC in 1990 was more dangerous than the Iraq War.

The Mother Jones article referenced above is arguing that the most effective thing that can be done to combat crime is lead abatement, I think that argument has taken a fatal hit. Some cities are in fact seeing homicide rates close to or even above the 1990s rates, that happened suddenly and it happened after leaded gasoline had been banned for 45 years.

You can't explain the massive increase in homicide in large cities in 2020 using environmental factors like lead, the cause has to be cultural or political.