[ItisaReligionofPeace]

Perhaps the sniper gave the police a phone booth number and told the cops to be there for the call?

[MagnumPi]

What if this is all a giant setup/trap. The possibilities are endless but this real life game of clue is mind boggling. Example-- Possibly they are trying to lure a large number of LE's into an ambush for a carbomb.
This is either terrorist or the most cunning mass murderer imaginable.