The Prague gunman who shot dead 14 people and injured two Emiratis had an arsenal of weapons such as long-barrel rifles and shotguns, leading to questions over whether the attack could have been prevented.
The 24-year-old gunman, identified as David Kozak, was a student with no criminal record and no known links to international terrorists or extreme ideologies, leaving his motive unclear.
Police are probing unverified claims that he ran a social media account that took inspiration from a Russian mass gunman, amid fears events in the Czech Republic will similarly inspire similar killers.
Investigations since Thursday’s attack have found he had a licence to own eight firearms including two long guns, had taken self-defence classes and is suspected of having killed a father and daughter.
A minute’s silence was held at noon on Saturday in a national day of mourning for the victims, with Czech President Petr Pavel among the worshippers at a service at Prague Castle’s Gothic cathedral.
The killer had opened fire at Charles University's arts faculty two days earlier, killing 14, injuring three and resulting in frantic scenes as students took refuge on roofs and balconies.
Authorities say the atrocity could have been worse after a cache of weapons and ammunition was discovered at the university.
The gunman had a “huge arsenal of weapons and ammunition”, said Czech police president Martin Vondrasek.
The killer had avoided attracting the attention of authorities before Thursday’s attack, but police now believe he was responsible for a shooting in a forest a week earlier.
A man and his two-month-old daughter were killed during a walk on December 15. Police have since found a ballistics match at the crime scene at Charles University.
Acquaintances who spoke to Czech media described the killer as quiet and bland. One was a training centre boss who confirmed Kozak had been on a self-defence course, which he said did not involve the use of firearms.
“The person was really bland, he didn't express himself and he was quiet, that's why the instructors didn't notice him too much. He didn't stand out,” Zdenek Charvat told the iDNES newspaper.
Mr Vondrasek said Czech police have been training for an active gunman scenario since far-right extremist Anders Behring Breivik killed dozens of people in Norway in 2011.
“That was the year when we realised it can happen anywhere in the world,” Mr Vondrasek said.
Czech gun laws are considered liberal by European standards, with the right to bear arms added to the constitution in 2021 in a measure compared to the US's Second Amendment.
Prospective gun owners must be at least 21, have a clean criminal record, pass both a theory and practical test and meet health requirements – conditions which the Prague gunman appeared to have met.
In the attack’s aftermath “it is logical to also talk about how to tighten up gun ownership, which the public has started calling for,” said Czech Interior Minister Vit Rakusan.
A new gun law was already being debated in parliament before Thursday’s attack, with proposals including new powers to check on people with an “abnormal accumulation of weapons”.
There are suggestions that doctors could also be given access to gun ownership records, allowing them to advise that a patient may no longer be fit to own a firearm.
Police in the Czech Republic have also increased security at “soft targets” such as schools that are difficult to protect, with extra guards to remain in place until January 1.
However, the Prague attack was a “completely unexpected act” and even stricter rules on gun ownership would not eliminate the risk of a future atrocity, Mr Rakusan said.
“If someone is determined to do it, even the best possible legislation could not prevent it,” he said.
