The FBI has released the transcripts of conversations between Omar Mateen, the Florida gunman, and the 911 emergency service, as well as with three crisis negotiators.
Mateen, whose June 12 assault on a gay bar in Orlando left him and 49 people dead, pledged his loyalty to the Islamic State of Syria and the Levant (ISIL) as well as some other often-conflicting groups, according to FBI.
The majority of the victims were lesbian, gay, bisexual and transgender people of colour, as it was a "Latin night" at the Pulse nightclub.
During the 50-second call, Mateen "made murderous statements" in a "chilling, calm and deliberate manner", Ronald Hopper, FBI assistant special agent in charge in Orlando, said on Monday.
However, there is no evidence that Mateen, who was born in the United States to Afghan immigrants, was directed by a foreign armed group, Hopper said.
Mateen's name and the groups and people to whom he pledged allegiance were omitted from the excerpt.
But the FBI has previously said he pledged allegiance to Abu Bakr al-Baghdadi, the leader of ISIL, also known as ISIS.
Shortly after the call, Mateen had three conversations with crisis negotiators in which he identified himself as a religious soldier and told a negotiator to tell America to stop bombing Syria and Iraq.
He said that was why he was "out here right now", according to the excerpt.
City officials have refused to provide hundreds of 911 calls to the Associated Press and a coalition of news organisations, citing confidentiality under Florida law, and arguing that an ongoing investigation kept the tapes secret.
Hopper also said that the tapes would not be released out of respect for the victims.
"Yes, the audio was compelling, but to expose that now would be excruciatingly painful to exploit them in this way," Hopper said.
Hopper said officials are "not going to propagate violent rhetoric" by giving full transcripts with no redactions.
The AP and others requested the 911 tapes and related data, a common practice after such major events.
The recordings could offer insight into how law-enforcement agencies responded.
Meanwhile, four people remain in a critical condition, according to hospital officials, more than a week after they were wounded in the nightclub attack.
Orlando Regional Medical Center said 18 victims of the shooting were still at the hospital as of Monday morning and three more surgeries were scheduled for the day.
The other 14 patients are listed in stable condition.
The transcripts were initially released in a heavily redacted form, but after criticism from Paul Ryan, Speaker of the House of Representatives, and others, the Department of Justice and the FBI released a full transcript of Mateen's first conversation with 911.
However, other phone conversations were ostensibly still being withheld from the public eye.
The FBI had previously said that Mateen had spoken with 911 three times, as The Intercept's Robert Mackey pointed out.
Ryan had issued a statement earlier in the day, decrying the redactions as "preposterous".
"The administration should release the full, unredacted so the public is clear-eyed about who did this, and why," he said.
Source: Al Jazeera and agencies