Texas Hostage Taker Identified as British Citizen Who Traveled to U.S. in Recent Days

An elite FBI rescue team that flew in from Quantico, Va., stormed the synagogue and freed three of the hostages, authorities said. One hostage was released earlier, and none were harmed.

A law-enforcement official with knowledge of the situation said Mr. Akram is believed to have flown from Britain to the U.S. in recent days. The official said investigators believe Mr. Akram used a handgun in the standoff, and they are working to figure out how and where he purchased it.

A Facebook post from Mr. Akram’s brother said the hostage taker was suffering from mental-health issues. In the post, Mr. Akram’s brother said his family had been following the Texas standoff from England and were in contact with the FBI and negotiators during the incident. The brother said his family never believed Mr. Akram would harm the hostages. He wrote his family was devastated by the situation and apologized to those taken hostage.

“There was nothing we could have said to him or done that would have convinced him to surrender,” the brother said in the post.

He claimed Mr. Akram was shot and killed during a firefight.

The post, which was shared by the Muslim community in Blackburn, England, was confirmed to be authentic by a British government official.

FBI agents are continuing to sift through evidence at the synagogue.

Matt DeSarno, special agent in charge for the FBI’s Dallas Field Office, said in the statement from the bureau that there is no evidence that any other individuals are involved. He also said the FBI’S North Texas Joint Terrorism Task Force is involved in the investigation.

The U.K. Foreign, Commonwealth and Development Office said it was aware of the death of a British man in Texas and is in contact with the local authorities.

Colleyville is a city with a population of around 30,000 in the Dallas-Fort Worth metropolitan area. Congregation Beth Israel, the synagogue where the standoff occurred, is a Reform Jewish congregation and was founded in 1999, according to its website.

Mr. DeSarno said Saturday that Mr. Akram “was singularly focused on one issue, and it wasn’t specifically related to the Jewish community.”

Mr. Akram claimed to law enforcement that he was the brother of a Pakistani woman convicted in 2010 of trying to kill U.S. Army soldiers, according to another law-enforcement official with knowledge of the case. Mr. Akram demanded that the woman, Aafia Siddiqui, be released from prison, the official said.

He also claimed to be armed and in possession of explosives, the official said.

Ms. Siddiqui is serving an 86-year sentence in a Fort Worth federal prison for the attempted killing of FBI agents and soldiers at an Afghan police compound in 2008.

Marwa Elbially, an attorney for Ms. Siddiqui, said the hostage taker wasn’t Ms. Siddiqui’s brother or related to her, and condemned his actions.

President Biden on Sunday called the synagogue standoff an “act of terror” and said he told the attorney general, “I wanted to make sure that we got the word out [to] synagogues and other places of worship that we’re not going to tolerate this.”

He also said he planned to call the congregation’s rabbi.

—Max Colchester in London contributed to this article.

Write to Dan Frosch at dan.frosch@wsj.com