When I read Batman stories as a kid/young adult (back in the last century), it also seemed to me that the area called "Crime Alley" didn't really earn its reputation and nickname until AFTER Thomas and Martha Wayne were killed there.
But in reading the recent Detective Comics (issue #939), it seemed from the flashback to the funeral for the Waynes that maybe it was already a known trouble spot even before they were shot there?
So, when did "Crime Alley" become known for crime and/or murder? And has the timeframe evolved and changed over time?