Terror investigators are looking for three other men in connection with the self-proclaimed jihadist who shot a Philadelphia police officer "in the name of Islam" and fear other cops may be in danger, NBC News has learned.
Senior law enforcement sources said members of a federal and local Joint Terrorist Task Force are taking seriously the statements of a woman who came forward over the weekend to report alleged gunman Edward Archer had ties to a trio with similar intentions.
"The threat to police is not over," the tipster said, adding that the men frequent a block around the corner from where the officer was shot and across the street from where Archer lives.
Investigators have learned the names of two of them but are still trying to identify the third.
In the meantime, Philadelphia cops are patrolling only in pairs, while authorities try to determine if Archer is a lone wolf or had help — in part by going through his electronic devices.
They want to know how an unemployed man with no prior foreign travel was able to obtain a passport and pay for an extended stay in the Middle East, the law enforcement sources said. They are trying to find out whether Archer's trips to Egypt and Saudi Arabia in 2011 and 2012 were funded by people or organizations with links to terrorism, the sources said.
Archer, 30, is charged with walking up to Philadelphia Police Officer Jesse Hartnett's patrol car and opening fire on him using a stolen gun. Hit three times in the arm, the five-year veteran managed to return fire and wound Archer, who confessed and said he had pledged allegiance to ISIS, according to police.
"This could easily have been a police funeral," Police Commissioner Richard Ross said after the shooting. "I don't know how this officer survived."
While Hartnett remains in critical condition, Archer was arraigned over the weekend on charges that include attempted murder, assault on a law-enforcement officer, and gun possession.
His prior criminal record includes a 2012 arrest for aggravated assault, a 2013 firearm conviction and a pending fraud case.
The tipster told police that Archer was affiliated with two mosques.
At one of them, the Association of Islamic Charitable Projects in West Philadelphia, administrators said that while Archer might have attended a service or taken a class, they did not know him as an active member.
They were adamant that he could not have been radicalized at their mosque and said Hartnett's shooting went against everything they stand for.
"We've been very diligent in combating radical ideologies," said Walid Dimachkie, an administrator. "We're mortified by the fact that there's someone out there who thinks that shooting a police office can be done — and condoned — in the name of religion."
Archer prayed at another mosque a block away from the shooting, where the imam at first denied knowing him but later told the Philadelphia Inquirer that he did recognize him but knew him under the name Abdul Shaheed.
There is no suggestion the mosques themselves played any role in the Thursday night ambush.