In addition to the point about under-reporting, which was already made here, the drop in tourists and commuters may also be masking a rise in crime in the data.

In addition to the point about under-reporting, which was already made here, the drop in tourists and commuters may also be masking a rise in crime in the data. To understand this, you first have to realize that crime is typically overstated in destination neighborhoods, because visitors to the neighborhood are not counted in the denominator of most crime statistics, which are calculated by dividing the number of incidents by the number of permanent residents. Given two neighborhoods with identical official crime rates, the one with more daily visitors actually has a much lower true rate. But in a year where the visitors fell off a cliff, you could have a drop in the number of incidents, which would show a decrease in crime in the official stats, even if there was actually an increase in the true rate of crime.