Personally I hate when people jump to rash conclusions in the first few hours after something like this happens and this is why I try to withhold making rash conclusions and wait to see what comes out.
The same sort of thing happens whenever there is a train derailment, industrial explosion, car running into a crowd, a random shooting by some lone psycho; unfortunately some immediately knee jerk that it must have been a Muslim terrorist or an illegal and when it comes out that is wasnt, some even seem disappointed. Its almost as if some people are looking for the next 9-11 and are disappointed when it doesnt happen. Quite frankly this sort of thing makes conservatives look bad. OTOH, the knee jerk reactions from the left and from the pop psychologists are just as bad.
At the end of the day, the families of the people who died or those who are seriously injured and their families probably dont care one wit whether it was some lone nut or a terrorist. Motivation, politics, race, mental illness, drug use, religion
at the end of the day it probably doesnt matter much to the dead, injured, traumatized and their families.