I was heading to my old house this evening after work (still getting the place ready to sell), and I almost had to divert elsewhere. The police were at the bottom of my block, and had the next block to the north and the one beside it to the east isolated: taped off, pairs of police cars in each intersection, and police officers with AR-15s patrolling each intersection and keeping everyone out.
The action (not that there was anything visible) appeared to be at the far end of the block to my north; there was a larger concentration of officers in the front yard of the house there, and when the police lines came down about an hour later, an ambulance showed up there.
According to one of my neighbors, the police had been there for probably three or four hours total. Be interesting to see what it was all about – radio news had nothing on it.