This is the 3468th most frequent Russian word.
прокуратуру
"Прокуратуру" means "prosecutor's office" or "prosecution office" in English.
In this sentence, 'прокуратуру' functions as a direct object, referring to the prosecutor's office being visited.
Я сегодня посетил прокуратуру.
I visited the prosecutor's office today.
Here, 'прокуратуру' is used as the destination indicating where the complaint was submitted.
Он подал жалобу в прокуратуру.
He filed a complaint to the prosecutor's office.
In this example, 'прокуратуру' is part of a prepositional phrase, showing the target of an action being planned.