There is a lot of false informations about the Prague shooting. Stay vigilant, listen to the current finding by Police and the government, remain open minded and verify the information prior to sharing them.

As of information that i was able to verify and how:
* The shooter has been identified as David Kozak by the police who reportedly fatally shot him in the university.
* Police found an "arsenal of weapons" in the charles university building, what classifies an arsenal and how did it get there is unknown to me.[1]
* Police suspects that shooting in the Planovicky forest which reportedly killed two people last week is related to this incident. [1.1]
* Reports on social media and allegedly by Nova TV say that the attacker used explosives, police was unable to verify the claim. The alleged claim by Nova TV might be police's use of flashbang or equipment alike that was misinterpreted.
* Video in the ref.2 likely shows the firefight between the shooter and the police where it's likely that the shooter got fatally shot (due to video quality it's hard to verify)
* The shooter reportedly took an inspiration from a fatal shooting in Berdyansk, russia on December 9th where 14yo Alena(?) shot two of her students, wounded others and then committed suicide, reportedly the shooter wrote this on his telegram prior to the incident. The report is considered low confidence as we can't prove beyond a reasonable doubt that the shooter owns the telegram account.[3]
* Shooter reportedly speaks Russian. (low confidence, due to lack of proof telegram channel ownership)
* Shooter is not known to be of Ukrainian nationality as claimed by evident troll farms and confirmed by the government.[1]
* Motivation of the shooter remains unknown, psychological disorder currently seems as the most logical explanation, but it's possible that his actions were rational.
* Express.cz claims that the police was looking for the shooter since morning the day of the incident[4]

References:
1. Police and government press briefing after the shooting https://tn.nova.cz/videa/5209-mimoradne-vysilani-tn-live/401261-policejni-prezident-objevili-jsme-obrovsky-arzenal-zbrani-a-streliva-primo-v-budove-skoly
1.1. Information about murders in planovicky lest at 01:21
2. Video that seems to show gun fire exchange between the shooter and police https://twitter.com/visegrad24/status/1737927748641759354
3. Hospodarske Noviny report on shooter taking inspiration by shooting in russia https://domaci.hn.cz/c1-67279020-jmenuji-se-david-chci-strilet-ve-skole-psal-utocnik-na-telegramu-inspiraci-mu-byly-strelby-v-rusku
4. Reportedly police was looking for the shooter prior to shooting - https://www.expres.cz/zpravy/strelba-filozoficka-fakulta-david-kozak.A231221_172238_dx-zpravy_stes/foto/STE9aa125edc3_Beznvdwqwfadwqdqzvu.jpg