There have to have been fired slugs recovered from both Brown and MIT. A very simple, basic, check could have verified/discounted the same firearm being used. How come we haven’t heard how that checked out? At a minimum if the same gun was used at MIT the folks at Brown could rest a little easier. Otherwise the Brownies still need to be on their toes.
Every Tesla along the shooter’s path would have video of him. Some likely from just feet away. Why is it so hard for the FBI to find him?