This is the 5670th most frequent Russian word.
преступлениями
"Crimes."
In this sentence, 'преступлениями' is the instrumental plural form of 'преступление,' used to denote 'crimes' with which someone is engaged or associated.
Он занимается изучением преступлениями своего города.
He studies the crimes of his city.
Here, 'преступлениями' is used in the context of specific instances of crimes encountered.
За годы он ознакомился с различными преступлениями, произошедшими в регионе.
Over the years, he became familiar with various crimes that occurred in the region.
In this example, 'преступлениями' is instrumental plural, providing details about the historical crimes discussed.