More than 24 hours after a shooting rampage at a popular gay nightclub here, the police chief offered new details Monday about the his officers’ confrontations with the gunman while other officials said that all but one of the 49 victims had been identified.
Dozens of bodies were removed overnight Monday from the nightclub, Pulse, and by early morning, 48 of the 49 victims had been identified, Mayor Buddy Dyer of Orlando said at a news conference, and the families of 26 victims had been notified.
At an early morning news conference, the police chief, John Mina, said police officers had three confrontations with the gunman, identified as Omar Mateen, who was killed by the police at the club early Sunday morning.
The first came when an off-duty officer who had been working at the nightclub responded to shots fired at about 2 a.m., Chief Mina said. Additional officers rushed to the scene, he said, and entered the nightclub where they engaged in a gun battle with Mr. Mateen, forcing him to retreat to a bathroom where officers believed he had four to five hostages. About 15 to 20 people were in another bathroom.
“At that time we were able to save and rescue dozens and dozens of people and get them out of the club,” Chief Mina said. A SWAT team was called and took up positions in a bathroom across from where Mr. Mateen had holed up.
Negotiators also began to talk with Mr. Mateen, whom Chief Mina described as “cool and calm.”
Mr. Mateen made statements that led police officers to think he was going to begin killing more people, the chief said, and he called 911.
“He really wasn’t asking for a whole lot, we were doing most of the asking,” Chief Mina said.
“Our negotiators were talking with him,” he said. “And there were no shots at that time but there was talk about bomb vests and explosives. There was an allegiance to the Islamic State.”
Chief Mina said Mr. Mateen’s talk of explosives spurred the police’s decision to start the rescue operation and try to breach the bathroom.
But an explosive placed on the wall did not penetrate completely, so officers used an armored vehicle to punch a hole about two feet off the ground, allowing hostages to flee. Mr. Mateen also came through the breach in the wall, Chief Mina said, and was killed in a shootout with the police.
When asked during the news conference if there was a chance that people might have been struck by friendly fire, or in the crossfire, Chief Mina said: “I will say that is all part of the investigation. But I will say when our SWAT officers, about eight or nine officers, opened fire, their backdrop was a concrete wall. And they were being fired upon, so that is all part of the investigation.”
At hospitals and gathering spots nearby, relatives and friends of the clubgoers who remained unaccounted for began to lose hope that their loved ones had somehow survived the mass shooting. And those who had already learned that their loved ones had died began to plan for funerals.
“I cannot imagine being one of the parents or knowing your loved one may be among the deceased and waiting to find out,” Mr. Dyer said. The authorities adjusted the death toll on Monday, saying that the 50 people killed included the gunman. Orlando Health, which has a network of medical facilities in the area, said 43 victims remained in the hospital, including six who would undergo operations on Monday.
Investigators continued on Monday morning to scour the crime scene for evidence and piece together the gunman’s motive. Thirty victim witness specialists and crime reconstruction experts were on the scene processing as much evidence as possible, F.B.I. officials said.
Mr. Mateen’s father, Seddique Mir Mateen, posted a video on his Facebook page early on Monday in which he expressed regret and confusion about why his son had carried out the mass killing.
“I don’t know what caused this,” said Mr. Mateen, speaking in Dari, a language spoken in Afghanistan. “I did not know and did not understand that he has anger in his heart.”
“My son, Omar Mateen, was a very good boy, an educated boy, who had a child and a wife, very respectful of his parents,” he said.
At Monday’s news conference, A. Lee Bentley, the United States attorney for Central Florida, said the investigators had collected a large amount of electronic and criminal evidence and were trying to determine whether Mr. Mateen acted alone.
“If anyone else was involved in this crime,” Mr. Bentley said, “they will be prosecuted.”
The attacker, a 29-year-old who was born in New York, turned what had been a celebratory night of dancing to salsa and merengue music at the crowded Pulse nightclub into a panicked scene of unimaginable slaughter, the floors slicked with blood, the dead and the wounded piled atop one another. Terrified people poured onto the darkened streets of the surrounding neighborhood, some carried wounded victims to safety and police vehicles were pressed into service as makeshift ambulances to rush people to hospitals.
Joel Figueroa and his friends “were dancing by the hip-hop area when I heard shots, bam, bam, bam,” he said, adding, “Everybody was screaming and running toward the front door.”
It was the worst act of terrorism on American soil since Sept. 11, 2001, and the deadliest attack on a gay target in the nation’s history, though officials said it was not clear whether some victims had been accidentally shot by law enforcement officers.