President Trump tweeted late Wednesday that the alleged terrorist who killed eight people in New York should get the death penalty.

“NYC terrorist was happy as he asked to hang ISIS flag in his hospital room. He killed 8 people, badly injured 12. SHOULD GET DEATH PENALTY!” the president tweeted.

Trump’s post came hours after details emerged in a criminal complaint that the suspect allegedly told investigators he “felt good” about carrying out the attack, and also asked to display flags of the Islamic State terrorist group in his hospital room.

On Tuesday, Sayfullo Saipov, a 29-year-old from Uzbekistan, allegedly rammed a truck into a crowded bike path near the World Trade Center Memorial, killing eight and injuring a dozen. 

Trump responded to the attack by pledging to increase vetting of immigrants entering the U.S. He also promised Wednesday to end the visa program that allowed the suspect into the country.

Trump also said he was considering sending Saipov to the U.S. military prison at Guantanamo Bay, Cuba.

Follow Ryan Miller on Twitter @RyanW_Miller