New York (CNN) Federal prosecutors will seek the death penalty against the suspect in New York's deadliest terror incident since 9/11, an attack that left eight people dead when a box truck went down a bicycle path.

Sayfullo Habibullaevic Saipov, who previously entered a plea of not guilty, faces an indictment that includes murder, attempted murder and terror-related charges in the October 31 rampage.

In a court filing Friday, prosecutors said Saipov, 30, committed the crimes "in an especially heinous, cruel and depraved manner." They also cited his alleged support of the Islamic State and lack of remorse.

The suspect's attorneys said in a statement that they were disappointed.

"We think the decision to seek the death penalty rather than accepting a guilty plea to life in prison with no possibility of release will only prolong the trauma of these events for everyone involved."

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