Malik Faisal Akram, the British terrorist shot dead in a hostage situation in a Texas synagogue, stayed in various homeless shelters in the Dallas-Fort Worth area and bought his guns 'on the street' just before the attack, the Daily Mail reported.
In a live Facebook feed, he was heard shouting at the congregation in a strong northern British accent: "If anyone tries to enter this building - everyone will die."
He added: "I'm gunned up. I'm ammo-ed up. Guess what, I will die. I am going to die, so don't cry for me," before hurling anti-Semitic insults, the report said.
The extent of his criminal record is not yet clear, but it may be that some of his offences may have been too petty or too old to stop him being turned away from the United States' border.
As the police in the US and the UK scramble to find if he was part of a wider terror cell, it has emerged that Akram, 44, from Blackburn, Lancashire, was branded a 'menace' for expressing his desire to be onboard one of the planes that destroyed the World Trade Centre in 2001.
It is also possible that his 9/11 rants and other crimes may not have been picked up if he lied about not being a criminal, because the US authorities do not routinely have access to Britain's criminal record information database, the report said.
Akram had apparently flown to America two weeks ago, lived in homeless shelters and bought a gun 'on the street', according to US President Joe Biden.
Akram's links to Pakistan are also being probed, having been a regular visitor to the country where his father was born. He was reportedly a supporter of the conservative Tablighi Jamaat group, set up to 'purify' Islam. While it denies being a terror group, its members are banned in Saudi Arabia after the organisation was branded 'one of the gates of terrorism' by the Gulf state.
Akram was banned from the Blackburn Magistrates' Court in September 2001 and was described as a 'menace' after officials complained that he was persistently causing trouble inside the magistrates' court even when he was not appearing before the bench.
The ban followed a series of incidents, which culminated with Akram abusing court ushers over the New York attacks.
Under the order, Akram was warned that if he entered the court complex, he could be detained under the Contempt of Court Act and face a possible prison sentence or 2,500-pound fine, the report said.
The rare Exclusion Order was made against him under Section 12 of the Contempt of Court Act and had only ever been used once before at the Blackburn Magistrates' Court.
A letter sent to Akram, known by his middle name Faisal, confirming the ban stated: "Once again you were threatening and abusing court staff. In a clear reference to the terrorist attack on New York, the previous day you said on more than one occasion to one of my court ushers 'you should have been on the f***ing plane'."
FBI special agent Matthew DeSarno told reporters in Colleyville, Texas, after the standoff that the investigation would 'have global reach'.
He said the suspect's demands were "focused on one issue that was not specifically threatening to the Jewish community".