When a gun-wielding suspect grew frustrated and belligerent that his demands were not being met, Rabbi Charlie Cytron-Walker felt he was facing a life-or-death situation, and he said he knew he had to take desperate measures if he and the two other hostages were going to survive.
"I guess you do what you have to do," Cytron-Walker said in an interview with CBS News on Monday morning, recounting the hours-long hostage standoff on Saturday at the Congregation Beth Israel synagogue in Colleyville, Texas.
Cytron-Walker said he was at the synagogue preparing for Shabbat services when the suspect, identified by the FBI as 44-year-old British citizen Malik Faisal Akram, knocked on a window of his temple near Fort Worth. Cytron-Walker invited him in for tea, thinking he was a troubled soul in need of prayer, the rabbi said.
"When I took him in, I stayed with him," Cytron-Walker said. "Making tea was an opportunity for me to talk with him, and in that moment I didn't hear anything suspicious."
He said that it wasn't until the beginning of the Shabbat service, attended by just a handful of congregants, that Akram let his true motives be known.
"While we were praying and my back was turned -- we face toward Jerusalem when we pray -- I heard a click," Cytron-Walker said. "And it could have been anything, and it turned out that it was his gun."
Law enforcement officials said they learned of the hostage-taking incident when members of the synagogue, many watching the ordeal unfold on an online livestream feed of the service, called 911.
As multiple police agencies surrounded the temple, Akram told hostage negotiators by phone that he wanted the release of a convicted terrorist who is incarcerated at Carswell Air Force Base near Fort Worth. In the livestream feed of the incident, Akram was overheard saying, "I'm going to die."
Akram flew to the United States from London on Dec. 29, landing at John F. Kennedy International Airport in New York, law enforcement sources told ABC News. According to the sources, Akram stayed at homeless shelters at various points and may have portrayed himself as experiencing homelessness to gain access to the synagogue during Shabbat services.
"We were threatened the entire time," Cytron-Walker said of the standoff that started just before 11 a.m. local time on Saturday and didn't end until after 9 p.m. "Fortunately, none of us were physically injured."
The rabbi said that during the ordeal, he kept thinking of the active-shooter drills he and members of his congregation had taken from the Colleyville Police Department, the FBI, the Anti-Defamation League and a local group called the Secure Community Network.
"They really teach you in those moments when your life is threatened, you need to do whatever you can to get to safety, everyone needs to do whatever you can to get out," Cytron-Walker said.
Initially, the rabbi and three male members of his congregation were taken hostage. About 5 p.m. on Saturday, the suspect freed one of them. But as time went on, Cytron-Walker said the suspect grew belligerent over his demands not being granted.
"The last hour or so of the standoff, he wasn't getting what he wanted ... it didn't look good, it didn't sound good," he said. "We were terrified."
Cytron-Walker said he decided to take action when the suspect moved away from an exit door.
"When I saw an opportunity where he wasn't in a good position, I made sure that the two gentlemen who were still with me ... were ready to go. The exit wasn't too far away," Cytron-Walker said.
He added, "I 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."
Video footage of the final moments of the standoff was captured by ABC Dallas affiliate WFAA and showed the hostages bolting out of a door followed by the suspect, who was holding a gun and quickly retreated back into the synagogue.
As flashbangs and gunfire went off, the WFAA footage showed an elite FBI hostage rescue team, which was flown in from bureau headquarters in Quantico, Virginia, storm the synagogue. The suspect was shot and killed by the hostage rescue team after it made what the FBI called the "deliberate decision" to breach the synagogue, multiple law enforcement sources told ABC News.
"It was terrifying. It was overwhelming, and we're still processing," Cytron-Walker told CBS News.
Cytron-Walker said he is looking forward to returning to his house of worship, describing it as a crucial step in the healing process.
"It won't necessarily be an easy thing," he said, "but it's a really important thing."