The article says the Saturday attack was the first in “recent memory”. I’d like to know how far back you’d have to go to find the previous such attack on a BART train. My guess is this is in fact the first *ever* with a group of attackers that large, and that the “in recent memory” bit is just there to downplay the fact that this is unprecedented. Could be wrong of course.
The Saturday attack was the only one I ever heard of on a BART train since BART began carrying passengers in 1972. Therefore, the first time was also the last time, i.e. Saturday evening.