(JTA) — Charleston church gunman Dylann Roof, whose racial manifesto said the Jewish “problem” would be solved “if we could somehow destroy the Jewish identity,” was sentenced to death on Tuesday for killing nine black worshippers.

Roof was sentenced in federal district court in Charleston, South Carolina, late on Tuesday afternoon for the June 2015 massacre of African-American worshipers at the Emanuel African Methodist Episcopal Church. He is the first person to be ordered executed for a federal hate crime.

Before the jurors began deliberating on Tuesday morning, Roof was given a last opportunity to plead for a lesser sentence. “I still feel like I had to do it,” he told the jury, the AP reported. “I have the right to ask you to give me a life sentence, but I’m not sure what good it would do anyway,” he also said.

Roof was convicted last month on 33 federal charges including hate crimes.

The Anti-Defamation League in a statement issued Tuesday said it “welcomed the closure” of the case, and called on the state of South Carolina to pass a state hate crimes law. Some 45 other states have passed hate crimes laws.

“Dylann Roof was an impressionable sponge, soaking in hateful content from the vehemently racist website Stormfront and other hate filled platforms,” said Oren Segal, director of ADL’s Center on Extremism. “In a period of only months, he had imbibed enough of the hateful ideology of the white supremacist movement that he was willing to commit murder to help achieve its twisted aims.

“Extremists from the Alt Right to ISIS are increasingly aware of how to exploit the Internet in order to achieve disproportionate visibility for their messages of hate and violence,” Segal said in the ADL statement. “More empty vessels like Dylann Roof will inevitably be filled with hate in the future.

Roof was a committed white supremacist and anti-Semite who wrote a manifesto outlining his views, yet never belonged to a white supremacist group or organization, according to the ADL.

The 2,500-word document is rife with racial hatred as well as spelling errors. The website also shows photos of Roof burning a U.S. flag and aiming firearms.

In his manifesto, which was published on a website registered in his name, and which was blocked shortly after his arrest a day after the murders, Roof calls Jews an “enigma,” adding, “I don’t pretend to understand why jews do what they do.” He said he believes that “the majority of American and European jews are White.”

“In my opinion the issues with jews is not their blood, but their identity. I think that if we could somehow destroy the jewish identity, then they wouldnt cause much of a problem. The problem is that Jews look White, and in many cases are White, yet they see themselves as minorities. Just like [the N word], most jews are always thinking about the fact that they are jewish,” Roof wrote.

He added: “The other issue is that they network. If we could somehow turn every jew blue for 24 hours, I think there would be a mass awakening, because people would be able to see plainly what is going on.”

Roof did not call any witnesses and did not call any mental health care professionals to discuss his mental state when he committed the murders during the penalty phase of the trial, where he represented himself.

In his journal, filed with racist and anti-Semitic rants, which was introduced as evidence during the trial, says he considers psychology a “Jewish invention.”

“It is a Jewish invention and does nothing but invent diseases and tell people they have problems when they don’t,” Roof wrote.