(Photo: Twitter)

(Photo: Twitter)

NEW YORK – Witnesses say Muslim terrorist Omar Mateen claimed to have multiple accomplices Sunday when he slaughtered 49 Americans and wounded 50 more at Pulse, a “gay” nightclub in Orlando, Florida.

And, though police say Mateen acted alone, a court-certified firearms expert and private investigator told WND he believes it’s possible there were other shooters involved in the attack.

One witness told ABC News’ “20/20” Sunday night that Mateen was calling people on the phone, telling them America must stop bombing ISIS in Syria.

“Then he called somebody else that he knew, and he mentioned that he was the fourth shooter and there was three others,” the unnamed witness said. “And then he mentioned, I believe, a female name [of someone] who was playing dead, because he was saying that she has a bombing vest and he has one too. And then he said there was three snipers out there, waiting for cops to come so the snipers would shoot at the cops.”

Watch the witness’ statement to “20/20”:

Another man named Richard Aiken, 29, told the Los Angeles Times he and Patience Carter, 20, were in the bathroom and overhead Mateen’s call.

“Aiken relayed what he and Carter heard: that the gunman claimed he had an explosive vest, that snipers were positioned around the club, that he had a female accomplice playing dead among the wounded, armed with explosives,” the Times reported.

None of the witnesses described physical features of any additional shooters – only the claims made by Mateen. Orlando Police tweeted Monday: “Alert: rumors of multiple shooters are unfounded. The one shooter, Omar Mateen, is dead.”

Orlando_police_tweet

Court-certified firearms expert and former Chicago police officer Paul Huebl said he believes Mateen may have had help.

“After seeing various anonymous posts on Facebook and Twitter from eyewitnesses to the shooting in Orlando, I began to realize the shooter most likely needed to make at least four magazine changes, yet none of the victims or potential victims apparently made any attempt to rush or overpower him,” Huebl explained to WND in an email and a telephone interview.

Huebl based his analysis on reasoning that the Sig Sauer MCX carbine used by the shooter – probably similar to weapons used by Orlando police SWAT teams engaged in the incident – most likely used magazines with a 30-round maximum.

“With some 50 people killed and another 50 wounded, that would have required four magazines, assuming only 20 rounds missed,” Huebl explained.

“According to press reports, many victims received multiple gunshot wounds, with some bodies reportedly being shot 10 or more times,” he added, concluding the shooter may have gotten off 200 or more rounds during the three-hours long incident.

Huebl told WND it may take an analysis of the shell casings in the nightclub to prove the point.

“My guess is that there are going to be 300-400 shell casings altogether,” he surmised. “The lead bullets will be too disfigured for positive ID, but an analysis of the shell casings should distinguish police SWAT teams from the perpetrators.”

Based on the information so far made available by federal and local law enforcement officials, Huebl believes it was nearly impossible for the shooter to have acted alone.

“The police negotiator who entered the Pulse nightclub apparently engaged the shooter in a firefight and apparently was not injured,” he said. “This should have created enough havoc with the shooter that, had the shooter been alone, I believe the victims could have had an opportunity to overpower the shooter, and possibly more would have escaped.”

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