▶ Watch Video: Hostage in Texas synagogue standoff tells of fears before escape

The investigation into the gunman who held four people hostage at a Texas synagogue Saturday has increased concern among federal officials about possible “copycat attacks,” according to an intelligence bulletin obtained by CBS News.

The joint bulletin was issued Tuesday to federal, state and local law enforcement partners by the FBI, Department of Homeland Security and National Counterterrorism Center.

Law enforcement sources say, and livestream audio of the incident reveals that the gunman, identified by authorities as 44-year-old British citizen Malik Faisal Akram, repeatedly asked for the release of Aafia Siddiqui, a Pakistani woman serving an 86-year sentence in a federal prison in Texas for trying to kill U.S. officers in Afghanistan.

Audio of the attack was captured on the synagogue’s live stream worship service for approximately the first 40 minutes, according to the joint bulletin. It remains unclear to investigators if the livestream was part of Akram’s plan, though federal law enforcement has identified the use of live streaming as a growing trend among violent extremists to try to amplify their attacks both domestically and abroad.

Tuesday’s bulletin cautions that “the hostage situation has reinvigorated online discussions, predominantly from … al Qaeda supporters, regarding Siddiqui’s detainment.”

Although there are “no known specific or ongoing threats to the Jewish community that have been identified related to this attack,” the FBI, DHS, and NCTC continue to “urge law enforcement partners to maintain a posture of increased situational awareness,” the bulletin says.

“The FBI, DHS, and NCTC also remain concerned about the potential for copycat attacks following this incident due to the volume of online violent extremist messaging advocating for the release of Aafia Siddiqui,” the bulletin reads. “Since the attack, open sources have reported online discussions — from a variety of sources, including AQ (al Qaeda) supporters — praising the attack and renewing attention on Siddiqui’s imprisonment.”

The advisory also points to recent al Qaeda-affiliated attempts to praise Akram and his violent actions. Editors of an al Qaeda-affiliated magazine released a statement Monday, commending and celebrating his actions, the bulletin states.

Since the attack, prominent al Qaeda backers have gone o private and public online sites to call Akram a “brother” and “martyr” for drawing attention to Aafia Siddiqui’s cause.

And while mainstream media outlets including Facebook and Twitter have been quicker to remove calls for violence in recent months, extremist actors have migrated to smaller, encrypted platforms such as Telegram, Element and “Rocketchat” to post such messages.

Details on Akram’s travel to U.S.

The bulletin states that Akram came alone to the United States on December 29, 2021, through the U.S. Visa Waiver Program.

His entrance into U.S. was approved by the U.S. Customs and Border Protection’s Electronic System for Travel Authorization, or “ESTA,” according to the bulletin, at New York City’s John F. Kennedy International Airport. Tourism visas are not required for British travelers planning to stay in the United States for less than three months.

Akram, who paid for his own flight from the United Kingdom to New York, did not appear on any U.S. terror watch lists, federal law enforcement sources previously confirmed to CBS News. He stayed in New York City for two days before traveling to Texas where, he told family members, he was hoping to find a bride.

The bulletin says the four hostages escaped before the FBI’s Hostage Rescue Team entered the synagogue.

“At approximately 10:11pm EST, as a tactical team approached to make entry to the synagogue, the hostages escaped and were secured by tactical elements,” the memo indicates.

“The assault team quickly breached the facility at a separate point of entry and the subject was killed.”

Rabbi Charlie Cytron-Walker, who was one of the people taken hostage, told “CBS Mornings” Tuesday that the situation seemed to be deteriorating near the end of the night.

According to the bulletin, Akram “told hostages he possessed guns and bombs and that he was ‘not afraid to pull the strings.'”

“I told them to go, I threw a chair at the gunman and I headed for the door,” Cytron-Walker recounted. “And all … of us were able to get out without even a shot being fired.”

Akram was later found to be in possession of just one firearm — a handgun he said he bought “on the street,” according to notes obtained by CBS News of a high-level law enforcement conference call led by FBI director Christopher Wray.

Increased focus of anti-Semitism in U.S.

According to the FBI’s annual data on hate crimes, incidents targeting the Jewish community in 2020 made up over half of all religion-based crimes. In 2020, the Anti-Defamation League recorded 327 anti-Semitic incidents at Jewish institutions such as synagogues, Jewish community centers and Jewish schools, an increase of 40% from 2019.

On Tuesday, Attorney General Merrick Garland, DHS Secretary Alejandro Mayorkas and the FBI’s Wray offered reassurance to more than 1,000 members of the Orthodox Jewish community during a teleconference, acknowledging the recent hostage standoff and underlining efforts to secure vulnerable Jewish institutions, nationwide.

Officials urged synagogue leaders to engage with local FBI field offices and participate in emergency preparedness measures, according to attendees.

Rabbi Cytron-Walker noted that he learned from security training sessions he attended prior to Saturday that “when your life is threatened, you need to do whatever you can to get to safety.”   

Mayorkas confirmed to reporters Monday that Cytron-Walker’s Beth Israel Congregation has received federal funding via the Nonprofit Security Grant Program, which grants non-profit organizations funds to expand their physical security footprint including fencing, cameras and security guards.

Funding for the program has skyrocketed in recent years, going from $20 million in 2016 to $180 million last year, according to the Federal Emergency Management Agency, which manages it.

On Monday, Mayorkas called on Congress to increase funding “so that our faith-based communities have the tools to upgrade their security and protect themselves against terrorism, hate crimes and targeted violence.”

In a tweet, the DHS secretary called the $180 million allotted in Fiscal Year 2021 “not nearly enough to meet the demand.”