The Islamic State, also known as ISIS, or its leader, Abu Bakr al-Baghdadi, were not mentioned in a partial transcript of the call the FBI released Monday morning. The agency said it didn't want to provide a platform to a terror group.
Republican House Speaker Paul Ryan was among the critics of the omissions, and the agency released the full, unredacted transcript of the call in the afternoon.
In explaining its change of mind, the FBI said in a news release: "As much of this information had been previously reported, we have re-issued the complete transcript to include these references in order to provide the highest level of transparency possible under the circumstances."
Mateen spoke to a 911 dispatcher at 2:35 a.m. June 12, more than 30 minutes after he first opened fire on the club.
"I let you know, I'm in Orlando and I did the shootings," Mateen told the dispatcher, according to the transcript.
When the dispatcher asked for his name, Mateen replied: "My name is I pledge of allegiance to Abu Bakr al-Baghdadi of the Islamic State."
The ISIS reference was not a surprise. CNN has previously reported that Mateen pledged allegiance to ISIS during a 911 call from the gay nightclub, citing a U.S. official.
Paul Ryan speaks out
Attorney General Loretta Lynch's decision to release only the partial transcript created a minor firestorm.
"Selectively editing this transcript is preposterous," Ryan said in a statement. "We know the shooter was a radical Islamist extremist inspired by ISIS. We also know he intentionally targeted the LGBT community. The administration should release the full, unredacted transcript so the public is clear-eyed about who did this, and why."
Authorities also defended the decision, saying it was meant to avoid lending credence to terrorist leaders.
"We're not going to propagate their rhetoric, their violent rhetoric," FBI Special Agent Ron Hopper said.
He also said the decision not to release audio, or details of victims' calls to 911, was to avoid further traumatizing those who were inside the club.
In addition to the transcript, the FBI released summaries of three calls between Mateen and crisis negotiators -- one at 2:48 a.m., another at 3:03 a.m. and the final one at 3:24 a.m.
In those calls, which lasted a total of 28 minutes, according to the FBI's timeline, Mateen identified himself as an Islamic soldier and "told the negotiator to tell America to stop bombing Syria and Iraq and that is why he was 'out here right now.' "
"When the crisis negotiator asked the shooter what he had done, the shooter stated, 'No, you already know what I did,' " according to the document.
He also claimed he had explosives in a vehicle outside the club and an explosive vest similar to those used by the Paris attackers
, and warned of similar attacks in the days to come.
Authorities found no explosives, and so far have found no credible threats of additional violence, Hopper said.
The timeline released by the FBI shows that the first call to police came in at 2:02 a.m. Within two minutes, officers were on the scene. At 2:08 a.m., officers entered the club and "engaged the shooter."
According to the timeline and Orlando police Chief John Mina, that's the last time shots were fired inside the club until nearly three hours later when police used explosives to blow a hole in the club's wall and an armored vehicle to enter the club.
By 5:15 a.m., Mateen was dead, according to authorities.
Police response defended
Mina and others defended the police response against what they said were misconceptions by some in the media and public about how events unfolded.
He said the initial engagement by officers minutes after the rampage began drove Mateen into hiding in a club bathroom and stopped the shooting.
He also said officers were in and out of the club, repeatedly rescuing people.
Hopper called the work of law enforcement officers that night "nothing less than extraordinary."
As for what motivated Mateen, FBI Special Agent Ron Hopper of Orlando said that authorities have no evidence that a foreign terrorist group directed his violent plot. Instead, they said, it appears he was radicalized domestically.
Investigators have conducted more than 500 interviews trying to determine his precise motive for the shootings, Hopper said.
On Monday, Orlando police said on Twitter that all streets near Pulse will be reopened overnight, except for the block in front of and of south the club.
Gun control measures
In the aftermath of the Orlando nightclub shooting, the four proposed gun control measures
up for consideration by the Senate failed to reach the 60-vote threshold required to pass on Monday.
The Senate rejected a Republican proposal to update the background check system for gun purchases to include information on mental health records in a national database. The measure included a provision calling for law enforcement agencies to be alerted when a gun is purchased by an individual who'd been on a government terror watch list in the last five years
Senators also defeated a Democrats' proposal to expand background checks on individuals to include gun shows and online purchases.
A Republican proposal to delay gun sales to individuals included on a government terror watch list failed in a mostly party-line vote of 53-47. And a Democratic option, proposed by Democratic Sen. Dianne Feinstein's, that sought to bar all gun sales to those individuals on the terror watch list, failed 47-53. This is the second time this measure has been defeated. Feinstein pushed the same proposal in December after the mass shooting in San Bernardino.
Senate Republicans said the Democratic measure that would ban gun sales to people on the terror watch list would violate individuals' Second Amendment rights. They said many people mistakenly end up on the federal terror watch list.
Meanwhile, Florida Governor Rick Scott said Monday that the Obama administration has rejected
the state's request for $5 million
in federal emergency funds following the nightclub shooting. The governor's press office referenced in a statement the $253,000 in federal assistance the state will receive to help pay overtime for the first responders following the attack.