Dennis, your son is correct, and it's documented. Putin may have used the conflict as an excuse to intervene or it may be one of many reasons.
I've listed sites that monitored the civil war because Dylan didn't site any evidence and wrote an opinion peace.
If you can separate Russia's invasion from the events occurring in Ukraine, you'd get a clear picture of what Ukrainians endured. Regardless of Russia's actions and excuses, the Ukrainian civil war was underway for almost a decade.
Ukraine: More than 14,000 casualties to date but ‘actual numbers are likely considerably higher'
https://news.un.org/en/story/2022/09/1126391
*The OSCE is a great organization for documenting the events and captured the build-up in the region just before Russia invaded.
The OSCE Special Monitoring Mission to Ukraine (SMM) started its activities on 21 March 2014 and discontinued its operations on 31 March 2022.
https://www.osce.org/special-monitoring-mission-to-ukraine-closed
Expressing its grave concern at the tragic events and violence in eastern
regions of Ukraine:
UN Documents for Ukraine
https://www.securitycouncilreport.org/un-documents/ukraine/
Donetsk News Agency:
An American freelance journalist visited the region and wrote this piece. You can brush it off as BS, but the established media reported this prior to Russia's attack on Ukraine. So, you can find this info via searching Ukraine civil war 2014, and the NYT, the Guardian, and numerous others published stories that validate the violence.
https://combatliberalismma.substack.com/p/god-will-sort-them-out-ukrainians
None of this justifies Russia - it simply explains Ukraine's history.