On 21 December 2023, a mass shooting occurred at Charles University's Faculty of Arts main building in central Prague, Czech Republic. A lone gunman, 24-year-old postgraduate student David Kozák, killed 13 people and injured 25 others before committing suicide after exchanging gunfire with police; an additional victim died indirectly from falling to her death while trying to escape the perpetrator.
At the time of the shooting, Kozák was one in a pool of about 4,000 suspects in a double murder that took place six days earlier, 25 kilometres (16 mi) away, when a man and his infant daughter were murdered in the Klánovice Forest. Evidence from the previous shootings linked the two incidents. Kozák's father was also found dead at his home in Hostouň, having been murdered hours before the Charles University shooting.
The Charles University shooting was the deadliest mass murder in the Czech Republic since its independence in 1993, surpassing the 2020 Bohumín arson attack.
Klánovice Forest murders and initial investigation
On 15 December 2023, a 32-year-old father and his two-month-old daughter in a stroller were shot dead in the Klánovice Forest on the eastern outskirts of Prague, approximately 25 kilometres (16 mi) away from Charles University. Later investigation revealed that the perpetrator, David Kozák, had only visited the Klánovice Forest once before committing the murders. On the day of the Charles University shooting, he had written a suicide note on his computer detailing the Klánovice murders; he had also hidden the murder weapon in the family garden. According to the letter, Kozák used public transport on the day of the murders and switched off his phone while changing transport on the other side of Prague. He carried a brown beige backpack and was armed with two handguns—a Glock 45 and a Beretta 71.
Upon entering the forest, Kozák initially wanted to shoot a woman with two children whom he saw at a playground along the main forest path, but then he noticed a man with a stroller heading towards a side path and decided that he was an easier target. Kozák followed him closely for a while before shooting the man multiple times using the Glock 45 pistol, which was equipped with a silencer. He then fired two rounds into the stroller, killing the man's infant daughter, before fleeing the scene.
Kozák fled on foot towards Úvaly, took a bus to Klánovice railway station, and left the area by train sometime between 16:00 and 16:45 CET. At some point during his escape, he passed by a couple with a stroller and considered shooting them as well but decided not to after hearing sirens in the distance.
The police conducted a detailed search of the entire forest with hundreds of officers, while a special task force was set up in order to find the perpetrator. As police had no direct leads, the scope of the investigation was first directed at owners of registered firearms matching the ballistic report from the crime scene, which initially limited the search to about 30,000 people. This was then further limited to 4,000 people, of which about 40 people lived in the vicinity of the Klánovice Forest. On 20 December, police said that they had no leads in the case but were continuing to search for the perpetrator.
Once a personal or work-related motive was exhausted, the investigation focused on the possibility of a random murder. The firearms website zbrojnice.com noted a similarity of the case with the 2005 "Forest Killer" murders, in which a former police officer killed three random victims in forests in preparation for a planned mass murder in the Prague Metro, which was prevented by his early arrest; the article ended with an appeal to readers to remain vigilant and carry their concealed firearms.
The chief detective of Prague's 1st General Crime Unit said that because Kozák lived in the Central Bohemian Region, which has a separate police directorate from Prague, they were a few days short of being able to prevent the Charles University attack.
Hostouň patricide and police manhunt
At an unknown time on 21 December 2023, six days after the Klánovice Forest murders, Kozák murdered his father, 55-year-old Stanislav Kozák, by shooting him three times in the head at their home in Hostouň, about 9 kilometres (5.6 mi) west of Prague. Stanislav was shot from behind with a semi-automatic variant of the Škorpion machine pistol while sitting at a table, before his body was moved and his neck was laid on a block of wood. An axe was found lying next to him, which indicated that Kozák had probably intended to cut his father's head off but did not do so for unknown reasons.
At 12:19 CET, the Central Bohemian Police received a call from Kozák's mother. One minute later, a friend of Kozák's, only identified as K.C., called the medical emergency line, saying Kozák was planning to take his own life. She also said that "[Kozák] could be dangerous", that he told her "he will do something she will hear about", and that he was on his way to Prague from his hometown of Hostouň. Police officers went to the Kozák residence at 12:33 and found his father's body, as well as improvised explosive devices that were decommissioned by specialists later that day. The police discovered that Kozák was a student of Charles University's Faculty of Arts in Prague. A search warrant was issued, indicating that Kozák was armed and dangerous.
At 13:10, the Central Bohemian Police, whose jurisdiction the village of Hostouň falls under, directly alerted the Prague Police. The Prague police dispatcher issued an all-points bulletin (APB), which said that Kozák was being sought due to suicide threats, that he may be dangerous, and that he also may be connected to a violent crime. A security operation was commenced at Václav Havel Airport near Hostouň, where Kozák worked alongside his father, a member of the airport security department. Prague Police also checked the Central Registry of Firearms, noting that Kozák owns multiple firearms, and that one of them was of the same type of focus in the Klánovice Forest murders investigation. The APB was expanded with information that Kozák should be considered extremely dangerous.
At 13:23, Kozák entered the Faculty of Arts main building on Jan Palach Square through the busy main entrance without arousing any suspicion. He was carrying a heavy suitcase containing firearms, a large amount of ammunition, cleavers, chains, and bicycle locks. Kozák proceeded to the fourth-floor bathrooms, where he apparently remained until the start of the attack. Before the shooting, he placed his ID, a floor plan of the fourth floor with handwritten notes about the classrooms' capacities, an unopened alcohol bottle, and a Rivotril pack under the bathroom window.
At 13:30, two police units, altogether six officers, entered the main building, where they talked to the reception personnel and two vice deans whom they met in the corridors. The officers searched the building's ground and first floors, then visited the Student Affairs Office and the Department of History. There, they learned that Kozák was supposed to attend a lecture starting at 14:00 in a different building on Celetná Street, a twelve-minute walk from the main building.
At 13:57, multiple police units were sent to evacuate the Celetná building, including the six police officers who searched the main building. They left without taking any further action and proceeded to the Celetná building, where they would stand guard until the start of the attack. At 14:04, the following information was relayed by the dispatcher through the police radio transmitter:
Increased caution for all patrols in the case of this Kozák. He's a really dangerous, very dangerous offender, suspect, and there's a lot of concern that he could use a weapon anytime, anywhere.