The creation of 3D printed guns by the neo-Nazi who launched a shooting attack in Germany must act as a warning to security services, experts have said.

Stephan Balliet only took one plastic weapon on the rampage that left two people dead in Halle but had manufactured several more, documents seen by The Independent reveal.

The 27-year-old livestreamed his attack in a move echoing the Christchurch shooting, and posted three documents online outlining his antisemitic and racist ideology.

But another cache of files that were not initially discovered online show Balliet had been making weapons before Brenton Tarrant’s atrocity in New Zealand.

Researchers at the International Centre for the Study of Radicalisation (ICSR), based at King’s College London, uncovered the extremist’s unseen original post on an obscure “chan” imageboard.

Germany synagogue shooting: Halle attack in photos Show all 24 1 /24 Germany synagogue shooting: Halle attack in photos Germany synagogue shooting: Halle attack in photos Police officers secure a synagogue in Halle. At least two people have been killed in the shootings at multiple locations in Germany AP Germany synagogue shooting: Halle attack in photos A man shots from a long-barreled gun ATV Studio Halle/Reuters TV Germany synagogue shooting: Halle attack in photos A police tank patrols at a crime scene near the Synagogue. The attack came during Yom Kippur, a Jewish religious festival that sees observers fast and pray at synagogues to atone for sins. EPA Germany synagogue shooting: Halle attack in photos The shooter walking in Halle ATV Studio Halle/Reuters TV Germany synagogue shooting: Halle attack in photos One victim's body was in the street outside the synagogue, while another victim was said to have been shot at a nearby kebab shop dpa via AP Germany synagogue shooting: Halle attack in photos Policemen climb over a wall close to the site of a shooting in Halle dpa/AFP/Getty Germany synagogue shooting: Halle attack in photos The shooting took place in the eastern German city of Halle, with the incident taking place on Humboldtstrasse, which houses a synagogue and Jewish cemetery Germany synagogue shooting: Halle attack in photos Synagogue's in over parts of Germany had a police officer presence, including Dresden AP Germany synagogue shooting: Halle attack in photos Local reports said one of the victims was killed outside a kebab shop around 600m away, where witnesses told Focus the assailant was wearing a helmet mounted with a camera, and wearing combat fatigues dpa/AFP/Getty Germany synagogue shooting: Halle attack in photos Police officer runs on a road in Halle dpa via AP Germany synagogue shooting: Halle attack in photos Police guard a crime scene EPA Germany synagogue shooting: Halle attack in photos Bullet casings after the shooting Reuters Germany synagogue shooting: Halle attack in photos Police officers block a road AP Germany synagogue shooting: Halle attack in photos A spokesperson for the local Jewish community told Der Spiegel that up to 80 worshippers were inside the synagogue at the time, but security measures at the synagogue's entrance "withstood the attack" Reuters Germany synagogue shooting: Halle attack in photos Policemen walk through a street close to the site of a shooting dpa/AFP/Getty Germany synagogue shooting: Halle attack in photos Policemen climb over a wall close to the site of a shooting in Halle an der Saale, eastern Germany, on October 9, 2019. - At least two people were killed in a shooting on a street in the German city of Halle, police said, adding that the perpetrators were on the run. "Early indications show that two people were killed in Halle. Several shots were fired. The suspected perpetrators fled in a car," said police on Twitter, urging residents in the area to stay indoors. (Photo by Sebastian Willnow / dpa / AFP) / Germany OUT (Photo by SEBASTIAN WILLNOW/dpa/AFP via Getty Images) SEBASTIAN WILLNOW dpa/AFP/Getty Germany synagogue shooting: Halle attack in photos Police secures the area after a shooting in the eastern German city of Halle on October 9, 2019. REUTERS/Marvin Gaul. NO RESALES. NO ARCHIVES STRINGER Reuters Germany synagogue shooting: Halle attack in photos Police secure the area Reuters Germany synagogue shooting: Halle attack in photos A police officer walks onto the street at the scene of a fatal shooting in Halle Nonstopnews/Reuters TV Germany synagogue shooting: Halle attack in photos Germany synagogue shooting - Multiple people dead as gunman on run in Halle MZTV Germany synagogue shooting: Halle attack in photos Police block the area around the site of the shooting dpa/AFP/Getty Germany synagogue shooting: Halle attack in photos First responders attend to the scene Nonstopnews/Reuters TV Germany synagogue shooting: Halle attack in photos Police gather Reuters Germany synagogue shooting: Halle attack in photos Police secures the area after a shooting in the eastern German city of Halle on October 9, 2019. REUTERS/Marvin Gaul. NO RESALES. NO ARCHIVES STRINGER Reuters

“For all of you, who live in no fun countries [with restrictive gun laws] this may be of interest,” Balliet wrote.

“All you need is a weekend worth of time and $50 for the materials.”

He wrote that he was about to start “live testing” before posting a link to the Twitch livestream that showed him carrying out the shooting.

The post was made at 11.57am on Wednesday, minutes before the attack on the synagogue, and Balliet could be heard typing and cursing on his livestream as he attempted the upload.

The downloaded folder contained the three documents that were shared widely online in the immediate aftermath of the shooting, but there was also a photo of Balliet and more folders containing detailed instructions on how to make homemade weapons.

It contained numerous files that could be run through a 3D printer to make the same firearms, as well as ammunition.

Balliet listed his primary objective as “proving the viability of improvised weapons”, although footage of the attack showed them jamming and failing multiple times.

ICSR research fellow Blyth Crawford said the documents claimed Balliet had been making his own guns for “years”.

People make a human chain around the synagogue and the Jewish cemetery targeted by neo-Nazi Stephan Balliet (AP)

She told The Independent the possibility of other terrorists using 3D printed weapons “needs to be responded to” by authorities.

“Designs for [one of Balliet’s weapons] have been around for a long time, but it is becoming more and more inexpensive to develop them,” she warned.

Rajan Basra, another ICSR research fellow, suggested there would have been a more urgent response from authorities if the attack had claimed more than two lives.

“There is a risk that because he didn’t succeed in launching a mass-casualty attack, it’s delaying the realisation that terrorists could use 3D printed guns,” he said.

“The reaction to attacks depends on the number of victims but the risk with that is that we miss longstanding trends, things that are staring us in the face.”

The shooting came just weeks after the first person was jailed for printing a 3D gun in the UK.

Tendai Muswere claimed the pistol, found during a London drugs raid, was for a prop for a university film project but was convicted for firearms offences.

British counterterror police have previously warned that the move from networked bomb plots to “low-tech” car and knife attacks had made attacks harder to prevent.

In Balliet’s case, German authorities have admitted that he was not known to be a security risk and had no criminal record.

Analysis of Balliet’s documents shows that several of the image files showing his plastic weapons were created on 8 March.

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The date is a week before the Christchurch attack in New Zealand, which had widely been considered the starting point of the following wave of far-right terrorist incidents including in Poway, El Paso and Norway.

“One line suggested the attacker had intended to create more weapons or do more attack planning but he abandoned that for reasons we can’t speculate on, and decided to conduct the attack on Yom Kippur,” Ms Crawford said.

Researchers said that because of the rapid adoption of new technology and platforms by young far-right extremists like Balliet, it would be impossible for his files to be completely removed from the internet.

Mr Basra called for authorities to encourage people to report suspicious offline behaviour, rather than solely using internet activity as an indicator of security risks.

“Balliet had been making weapons for a couple of years, he had been planning attacks for months,” he added.