COLLEYVILLE, Texas — An armed man who took four people hostage during a 10-hour standoff at a Texas synagogue had spent time in area homeless shelters in the two weeks leading up to the attack.

Wayne Walker is the CEO of OurCalling, a Dallas facility that provides services to homeless people. He said 44-year-old Malik Faisal Akram spent the night of Jan. 2 there.

“He was dropped off (at the synagogue) by somebody that looked like he had a relationship with him,” said Walker, who said they’d turned photos and video over to the FBI.

Rabbi Charlie Cytron-Walker, who was among the four taken hostage at Congregation Beth Israel synagogue, told “CBS Mornings” Monday that he’d let Akram into the building on Saturday morning because he appeared to need shelter.

Cytron-Walker says the man was not threatening or suspicious at first. Later, he heard a gun click as he was praying.

During the hostage negotiations, Akram demanded the release of a Pakistani neuroscientist who was convicted of trying to kill U.S. Army officers in Afghanistan.

Cytron-Walker later told CBS Mornings that he and two others were able to escape the building after he threw a chair at the gunman after a 10-hour standoff.

The FBI on Sunday night issued a statement calling the ordeal “a terrorism-related matter, in which the Jewish community was targeted.”

Two other suspects were arrested in the U.K. Monday in connection with the incident.

The synagogue is in Colleyville, a city of about 26,000 people located northwest of Dallas.