A day after Philadelphia Police reported that an anonymous tipster told officers the attack on one of their own was not an isolated event, paperwork of the report surfaced online.

RELATED: Donations pour in for family of Philly cop shot in 'ISIS'-related attack

The handwritten document is authentic, Public Affairs Officer Tanya Little confirmed, but she said the police department did not formally release it to the public. The report was posted on the Philadelinquency blog, which said police "publish[ed] the complaint."

The urgency of the potential threat to police comes through in the handwritten report filed on Saturday, two days after Officer Jesse Hartnett was wounded in an ambush-style shooting by Edward Archer, who told police he attacked the officer out of allegiance to ISIS.

RELATED: Man who shot Philly cop claims he did it 'in the name of Islam'

Below see the entire text of the report, taken from an anonymous woman who approached an officer at 60th and Walnut:

"Compl. stated to police that the threat to police is not over. She said that the offender who shot P/O Hartnett is part of a group that consist of three others and that the defendant is not the most radical of the four. And the other three males still frequent the 6100 block of Pine and for the police to be careful. Female also stated that the defendant was a part of the mosque on 60th St. But became more radical after he attended the mosque on 45th and Walnut. That the Eman [sic] on 60th St was lying when he said the defendant had no association with that mosque."

The police department announced Sunday that they had received the tip and that they were investigating it, along with the FBI. None of the information from the anonymous tipster has been reported, confirmed or verified at this time.

Archer, 30, is charged with attempted murder for shooting 11 rounds at Hartnett, 33, some at point-blank range, striking him four times in the arm and buttocks.

People who knew the gunman said he was a devout, quiet Muslim who became more "combative" after trips to Egypt and Saudi Arabia.

They said he began expressing interest in Islam as a teenager, played in a local Muslim football league and worked on construction jobs.

The imam of a local mosque where Archer worshipped, Asim Abdur Rashid, said Archer’s Muslim name was Abdul Shaheed. He said Archer had attended the West Philadelphia mosque, known as Masjid Mujahideen, for at least five years. He saw him as recently as last week.

“He was intelligent, and he was a regular dude,” Rashid said.

Rashid added that Archer regularly attended morning and evening prayers, in addition to midday Friday prayers.

FBI Special Agent Eric Ruona said Archer had traveled to Saudi Arabia in 2011 and Egypt in 2012 — a trip that a family friend said had changed him.

"He became more drastic. More combative," said Jannah Abdulsalaam, who asked only to be identified by her Muslim name. "He was kind but I noticed that change."

Additional reporting by Reuters