"The British man shot dead in the Texas synagogue siege was investigated by MI5 in late 2020, Whitehall sources confirmed to The Times."

"Malik Faisal Akram, 44, was the subject of a 'short lead investigation' for at least four weeks.... The authorities were already facing questions about why Akram was able to travel to the US, where he purchased a handgun, given he had a criminal record for offences including violence... Akram, from Blackburn, who once ranted about the September 11 attacks, was part of MI5’s pool of 40,000 closed subjects of interest.... The case was closed before it progressed to a full-blown inquiry involving intrusive techniques such as eavesdropping.... When he travelled to the US in late December, Akram was not on the Home Office warnings index, the watchlist that allows police at airports to intercept would-be passengers of concern. Sources said that it would be 'disproportionate' for someone assessed as being no threat to be on the list."

The London Times reports.

I'm sure you've read elsewhere that the rabbi engineered the escape — which involved throwing a chair at the armed hostage-taker. I like this justifiably proud statement by the rabbi, Jeffrey Cohen: "We escaped. We weren’t released or freed."