A man who sold a pistol to a man who used it to hold four hostages inside a Texas synagogue before being fatally shot by the FBI was sentenced Monday to nearly eight years in prison for a federal gun crime, the U.S. Department of Justice said.

Henry “Michael” Dwight Williams, 33, pleaded guilty in June to being a felon in possession of a firearm, prosecutors said. Williams sold Malik Faisal Akram the weapon Arkam used when he entered Congregation Beth Israel in the Dallas-area suburb of Colleyville on Jan. 15 and held the synagogue’s rabbi and three others hostage, according to prosecutors.

Williams, who was previously convicted of aggravated assault with a deadly weapon and attempted possession of a controlled substance, sold Akram a semi-automatic pistol on Jan. 13. Prosecutors said that in plea papers, Williams admitted to possession of that firearm despite his prior conviction.

“This defendant, a convicted felon, had no business carrying — much less buying and selling — firearms,” U.S. Attorney Chad Meacham said in a news release.

Prosecutors said Williams confirmed selling Akram the handgun at a Dallas intersection.

Akram, a 44-year-old British citizen, held hostages while demanding the release of a federal prisoner. The standoff ended after more than 10 hours when the temple’s rabbi threw a chair at Akram and fled with the other two remaining hostages just as an FBI tactical team was moving in. None of the hostages were injured.

Rabbi Charlie Cytron-Walker told CBS News shortly after the incident that he “told them to go, I threw a chair at the gunman and I headed for the door. And all three of us were able to get out without even a shot being fired.”   

Law enforcement officials praised Cytron-Walker for remaining calm and collected during the ordeal. 

Cytron-Walker said his response was informed by different courses he had attended over the years with the FBI, the Colleyville Police Department, the Anti-Defamation League and Secure Communities Network. 

“They really teach you in those moments that when your life is threatened, you need to do whatever you can to get to safety. You need to do whatever you can to get out,” he said. 

Williams was arrested just over a week after the standoff.