NEW YORK -- Federal prosecutors on Wednesday filed terrorism charges against bike path attack suspect Sayfullo Saipov, who is accused of killing eight people and injuring a dozen others when he drove his car along a bike path in lower Manhattan Tuesday.

Saipov was taken to court the New York federal courthouse Wednesday in a wheelchair with his hands cuffed and feet shackled.

Saipov is charged with two terrorism counts: a charge of providing material support to a terrorist organization and a charge of violence and destruction of a motor vehicle with willful disregard for human life.

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Federal prosecutors say he was "consumed by hate and a twisted ideology" when he attacked people on the bike path on Tuesday.

New York City attack suspect Sayfullo Habibullaevic Saipov shown in court Wed., Nov. 1, 2017. Jane Rosenberg

The NYPD said Wednesday that Saipov, who came to the U.S. from Uzbekistan, had been planning the attack for two months and that he did a test run on October 22.

According to John Miller, NYPD deputy commissioner for counterterrrorism, Saipov had several pages of handwritten notes just outside the rental truck he used to ram into civilians, one of which said ISIS would "endure forever." The notes also used the phrases "no god but God and Muhammad is His true prophet," both of which are sayings affiliated with ISIS.

Prosecutors said they found two cellphones at the scene, with one of the phones containing 90 videos and thousands of images associated with ISIS. Saipov told investigators he was inspired to carry out the attack based off videos he watched on his cellphone.

A look at the suspect in the deadly truck attack in New York City. CBS News

Additionally, Saipov asked to fly the ISIS flag in his hospital room, according to the criminal complaint. He told investigators he felt good about what he had done.

According to the criminal complaint, Saipov chose Halloween for the attack because he believed there would be more civilians on the street for the holiday.

An intelligence source told CBS News' Pat Milton that Saipov was on authorities' radar before Tuesday.

After colliding with a school bus during the attack, Saipov allegedly exited the truck and yelled "Allahu Akbar." An NYPD officer shot him afterward, and he is currently hospitalized.

A family friend with whom the man stayed in Ohio has told The Cincinnati Enquirer he was "really calm" and worked hard.