This is the 14646th most frequent Turkish word.
polisleri
"Polisleri" means "the police" (plural or accusative case) in Turkish.
Here, 'polisleri' functions as the plural accusative case indicating the direct object referring to multiple police officers.
Parkta polisleri gördüm.
I saw the police in the park.
In this sentence, 'polisleri' is the plural accusative case marking the direct object of the imperative verb 'wait'.
Polisleri burada bekleyin.
Wait for the police here.
The word 'polisleri' again serves as the plural accusative case identifying the object of the verb 'investigating'.