This is the 8466th most frequent Swedish word.
begångna
"Begångna" means "committed" (as in acts or deeds, often crimes).
In this sentence, 'begångna' functions as a past participle (plural form) describing mistakes (misstagen) that were made/committed.
De begångna misstagen hade stora konsekvenser.
The committed mistakes had large consequences.
Here, 'begångna' is used as a descriptive term for crimes (brotten), providing information about the actions associated with them.
Ansvaret för de begångna brotten låg hos individen.
The responsibility for the committed crimes rested upon the individual.
In this sentence, 'begångna' modifies 'handlingarna' (the acts), indicating that these actions were completed or carried out.