During which step in the pretrial activities does a judicial officer determine if a crime has been committed?

Preliminary hearing

Explanation:

A preliminary hearing is the first hearing or a preliminary examination by a judicial officer which takes place after when a criminal complaint has been lodged or filed by a prosecutor. It is used to determine the if there is enough proof or evidence to require for a trail.

It is the proceeding which takes place before the criminal trial where a judge examines whether a crime has bee committed or not.