One of the men on trial for allegedly planning to attack soldiers on Fort Dix spoke with police, then an FBI agent, about his concerns that a man had asked him for a map of the Army installation.

It will be up to the jury to try to sort out whether Serdar Tatar was genuinely concerned, as his lawyer contends — or engaged in a game of "spy vs. spy," trying to smoke out an informant, as the government says.

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On Wednesday, the 20th day of the trial, jurors heard from the police officer.

The five accused men, all in their 20s at the time they were arrested in May 2007, are foreign-born Muslims who lived for years in the comfortable Philadelphia suburb of Cherry Hill. No attack was carried out.

They're charged with conspiracy to kill military personnel, attempted murder and weapons offenses and, if convicted, could face life in prison.

Prosecutors say the plot is one of the most frightening examples of homegrown terrorism. Defense lawyers, though, deny the men were seriously planning anything and note that a key government witness, Mahmoud Omar, was being paid $1,500 a week to be an informant.

On Wednesday, prosecutors called Philadelphia Police Sgt. Sean Dandridge to testify.

He told jurors that while working a beat in North Philadelphia in 2006, he stopped at a local convenience store every day to buy coffee. Over time, he got to know Tatar, who was the store's assistant manager.

Tatar, a high school dropout born in Turkey and a newlywed, told Dandridge that he wanted to be a police officer. He said he had taken — and failed — entry exams for the departments in Oakland, Calif., and Temple University.

Tatar invited the officer to go shooting with his friends and showed him video he took on his cell phone of the men firing weapons at a range in the Pocono Mountains in Pennsylvania.

When Dandridge stopped by on Nov. 15, 2008, he said, Tatar said he had something important to tell him — something involving a national security matter.

"This gentleman had approached him for a map of Fort Dix," Dandridge testified.

The map, Dandridge said, was at Tatar's father's pizza shop in Cookstown, just a few miles from Fort Dix. The man who asked for it was Omar, who turned out to be an FBI informant.

Dandridge was concerned enough that he called the FBI from the office at the back of the convenience store, and he and the clerk kept talking about the incident over the next few weeks.

A Philadelphia police detective assigned to an FBI anti-terrorism task force met with Dandridge Dec. 6, 2008 to discuss the matter and interviewed Tatar the next day.

"Tatar indicated that Omar suggested doing something bad to the base," said James Rycek, the task force officer, "some kind of terrorism-related act."

Both Dandridge and Rycek testified that Tatar told them he didn't hand over a map to Omar or anyone else.

However, according to a recording secretly made by Omar that the jury has already heard, Tatar did provide the map between the time he approached Dandridge and the time Rycek interviewed him.

On the recording, Tatar says he doesn't know if Omar is a "fed."

Omar, a 39-year-old Egyptian with a history of bank fraud, jokingly replies "I'm George Bush."

Finally, Tatar does give Omar the map. "I'm doing it," he says. "In the name of Allah."

Rycek said Tatar told him during the interview that he was concerned that Omar may have been an undercover immigration official looking to deport him. That could support the government's contention that Tatar was planning an attack and was slyly trying to determine with Omar was trustworthy.

However, on cross examination from Tatar's lawyer, Richard Sparaco, the officials also conceded that Tatar gave the FBI his accurate real name, phone number and address.

The trial is scheduled to resume Monday, with testimony from a second paid informant after a recess for Thanksgiving.