FBI shoots down cellphone story about Vegas attack

FBI: Story of alleged July 4 attack 'not credible'

Michael Hamdan said he overheard a suspicious coversation on his cellphone.

WASHINGTON (CNN) -- A man who told the FBI that he overheard a cell phone conversation about a possible Fourth of July terrorist attack in Las Vegas is "not credible," the FBI said late Friday.

"The results of the investigation to date do not substantiate these allegations, and the FBI has determined that this information is not credible," said Ellen Knowlton, special agent in charge of the Las Vegas FBI office, in a statement.

FBI Special Agent Daron Borst told CNN the probe was "substantially complete" after agents spent four and a half hours questioning Michael Hamdan and giving him a polygraph test Friday. Borst declined to discuss results of the test or elaborate further about the investigation.

CNN NewsPass VIDEO KLAS affiliate's George Knapp talks with a man who said he intercepted a cellphone call in Arabic that suggests a plot to attack Las Vegas, perhaps on July 4. (June 21) Play video   MORE STORIES Lawmakers question whether the proposed Homeland Security Department will do a better job than the CIA or the FBI.

Hamdan, a naturalized citizen who moved to the United States 25 years ago and is now semi-retired from a career in international marketing and exporting, reported the information to the FBI, which is investigating the call he said he overheard by chance last Saturday.

Hamdan said the callers were speaking Arabic, which Hamdan, a native of Lebanon, understands. Law enforcement sources said that coincidence was part of the reason for their skepticism.

Hamdan said he called the FBI twice starting at 2 a.m. Sunday, but didn't get a call back until Tuesday, after he had provided the information to local news media.

The overheard phone discussion involved an "Independence Day" attack in "the city of prostitution and gambling, the city of the unbelievers," Hamdan said.

"I felt shocked, I felt stunned," he said.

Hamdan, who worked for IBM in Kuwait and Cartier in France before moving to the United States and taking jobs in New York and California, said his initial shock evolved into a feeling of anger that "people were trying to hurt us. We should not be afraid in our own country. The people who want to hurt us should be afraid."

Hamdan said he was driving along Las Vegas Boulevard when he picked up his cellphone -- a German-made Siemans that can receive international and domestic signals -- to call his wife to tell her he was on his way home.

"I dialed the number and I pressed 'send,' and it seems the call didn't go through. So I listened. There was no click, nothing," he said.

"I was going to hang up when I heard somebody talking in Arabic. It seems another line crossed my line. I am from Lebanon originally, and I understand very well Arabic. As curious as any person, I want to listen to see what is this call."

He added, "All of the conversation was in Arabic, not even one word in English."

He said it sounded as if a group of people at one end of the line were talking to an individual, who appeared to be receiving instructions.

"We are here in the city of corruption, the city of prostitution and gambling, the city of the unbelievers," Hamdan said he heard someone say.

"And they are talking about freedom: 'We are going to hit them on the day of freedom,'" he said.

"When they say we are going to hit them on the day of freedom, you know the freedom for us, for all Americans, is Independence Day, the Fourth of July," Hamdan said.

Asked how he knew possible violence was afoot, Hamdan told CNN, "The tone of voice and the words have been really carefully chosen. The other individual -- he was only answering with 'OK, OK,' as if he was getting instruction."

According to Hamdan, the person's response in Arabic was more affirmative than the American term OK -- more similar to "I understand."

In earlier comments, Hamdan said the plot involved a bomb attack. However, he made no mention of a bomb in an on-air interviews with CNN.

Calls can be misdirected

Cellular telephone calls are handled on wireless communications networks that use transmitting sites or "cells" often seen as radio towers along highways.

As calls are processed, calls can be misdirected and inadvertently picked up by other users.

Cellular companies have helped law enforcement track individual user proximity to those sites and can report direction of travel as the sites hand off a call to the next location.

Many providers keep a detailed log on calls that have been handled by their systems such as the user's number, the call's date and time, and which cell sites were used.

It's possible to illicitly intercept the radio signals of cellular phone calls and hear a conversation using "scanners" or older television sets with UHF tuners that go to Channel 83. A portion of the upper UHF television spectrum was allocated to cellular telephone use.