NYPD Deputy Commissioner of Intelligence and Counterterrorism John Miller said in a press conference on Wednesday morning that terrorist Sayfullo Saipov acted “in the name of ISIS” and followed the Islamic State’s instructions for vehicular jihad “almost exactly to a T.”

“It appears that Mr. Saipov had been planning this for a number of weeks,” said Miller. “He did this in the name of ISIS, and along with other items recovered on the scene were some notes that further indicate that he appears to have followed, almost exactly to a T, the instructions that ISIS has put out to its followers on how to carry out such an attack.”

Miller said the other items recovered from around the vehicle included “multiple knives.” He described the notes as “handwritten in Arabic, they had symbols and words, the gist of the note was that the Islamic State would endure forever.”

In November 2016, the Islamic State magazine Rumiyah published a 46-page guide to “Just Terror Tactics” with a heavy emphasis on vehicle attacks, citing the July 2016 slaughter of 86 innocents with a truck in Nice, France as an example of vehicular jihad done right.

Rumiyah called for mass-casualty vehicle attacks on the upcoming Macy’s Thanksgiving Day Parade, describing it as an “excellent target,” but the very same NYPD counterterrorism commissioner, John Miller, said his department was well aware of the threat and was taking all necessary precautions.

The Islamic State’s advice for aspiring truck jihadis includes obtaining a “double-wheeled, load-bearing” truck with “slightly raised chassis and bumper,” capable of “fast speed or rate of acceleration.” The truck would be ideally borrowed or stolen from a “kafir” (non-Muslim). Gassing up and mapping out the route of attack were also recommended preparations.

“In general, one should consider any outdoor attraction that draws large crowds,” the terrorist manual advised. “The target should be on a road that offers the ability to accelerate to a high speed, which allows for inflicting maximum damage on those in the vehicle’s path.”

“Though being an essential part of modern life, very few actually comprehend the deadly and destructive capability of the motor vehicle and its capacity of reaping large numbers of casualties if used in a premeditated manner,” the ISIS magazine observed.

Rumiyah recommended using “the language of force, the language of killing, stabbing and slitting throats, chopping off heads, flattening them under trucks, and burning them alive, until they give the jizyah while they are in a state of humiliation.” The jizyah is a special tax collected from non-Muslims to indicate their submission to Muslim conquerors. Knives, arson, and kidnapping schemes were also presented as “just terror tactics” in the ISIS guidelines.

Also noteworthy is Rumiyah’s advice to make sure the attacker’s motives and loyalty to ISIS are properly declared: “An example of such would be simply writing on dozens of sheets of paper, ‘The Islamic State will remain!’ or ‘I am a soldier of the Islamic State!’ prior, and launching them from the vehicle’s window during the execution of the attack.” This appears to be precisely what Saipov did.

Other Islamic State media sources have called for vehicle jihad attacks. For example, at the end of the 2017 Ramadan holiday, the pro-ISIS Nashir News produced a poster that showed an SUV sporting a black ISIS flag driving over a mountain of skulls beneath the legend, “Run Over Them Without Mercy.”