Public transit in Rhode Island is mainly buses, although there's been a train that goes to Boston. Access is mainly at ground level. To the best of my recollection, there are no public transit facilities with elevators, except at the airport. If he's from Rhode Island, or adjacent areas in Connecticut or Massachusetts, he probably has a car. It's hard to live without one.
All RI, but especially Brown area, is quite compact. He might know it well (he seems to), but by the same token, he would be recognized if he were a local living around Brown U. People cluster in the same places.
Yet he seems to know the cameras. I remember the complaints of students/postdocs attending Brown over a decade ago, when there were fewer cameras around.
They complained that the area around Brown was frequently robbed, and very quietly so. It seems that all the thieves needed to know was the schedule. Entering when everyone is out, students don’t keep huge locks anyhow, and stealing money or jewelry or small electronics would be such a nonchalant routine... I don’t know if it was local mafia, amateurs or something in between. They never got in trouble and there was no violence associated with robbery. Usually thieves and mass shooters don’t merge, but thieves in the U-districts would have all the necessary knowledge. Just an idea.
Either a person familiar with the area from thieving, or regular delivery driver, or maybe someone working in one of facilities (e.g. geriatric) around Brown, too. No one notices the people working there.
The shooter is rather imperceptible (my guess about his ethnicity is as random as anyone’s, but just my guess why people have trouble figuring it out: it is one of the few groups with variable phenotypes; highly ethnically diverse). I would say that he looks bundled up so proportions from the back, shape of shoulders, height might be more telling.
And I think he is pretty sick, but I doubt he killed himself. I wonder if he merely went home, tbh.
