ORLANDO: Police Account of Decisions Made During Orlando Rampage Contains Crucial Gaps

Scores of people were already lying dead or injured inside a crowded Orlando nightclub, and the police had spent hours trying to connect with the gunman and end the situation without further violence. But when Omar Mateen threatened to set off explosives, the police decided to act, and pushed their way through a wall to end the bloody standoff.

That was a critical decision — one of many made by the police early on Sunday during the mass shooting at Pulse, a gay nightclub, that left 50 people dead, including the gunman, the authorities said.

A day after the shooting, many details of the police response remained in question, and the police account continued to contain crucial gaps — perhaps most critically, what happened during the hours that Mr. Mateen was hiding in a nightclub bathroom as he spoke intermittently to the police by cellphone.