(16.5.2017) The F.B.I.’s thinking crystallized by mid-August, after the C.I.A. director at the time, John O. Brennan, shared intelligence with Mr. Comey showing that the Russian government was behind an attack on the 2016 presidential election. Intelligence agencies began collaborating to investigate that operation. The Crossfire Hurricane team was part of that group but largely operated independently, three officials said.