725 ILCS 5/107-16: Apprehension of offender.

It is the duty of every sheriff, coroner, and every marshal, policeman, or other officer of an incorporated city, town, or village, having the power of a sheriff, when a criminal offense or breach of the peace is committed or attempted in his or her presence, forthwith to apprehend the offender and bring him or her before a judge, to be dealt with according to law; to suppress all riots and unlawful assemblies, and to keep the peace, and without delay to serve and execute all warrants and other process to him or her lawfully directed.