WARSAW — President Obama on Friday deplored the shooting deaths of five police officers in Dallas, saying there was “no possible justification” for such a “vicious, calculated and despicable attack on law enforcement.” “We are horrified over these events,” he said, “and we stand united with the people and the Police Department in Dallas.” Mr. Obama said that he had spoken to Mayor Mike Rawlings of Dallas, and that the F.B.I. was in contact with the Dallas authorities. The president said nearly a dozen police officers had been shot, several were wounded, and five had died/Associated Press. More here.