ST. LOUIS • St. Louis police arrested a fourth suspect Thursday in the slaying of Zemir Begic, a Bosnian immigrant who was beaten to death in a hammer attack.

The suspect is a 16-year-old male, police spokesman Schron Jackson said.

The teenager was arrested Thursday morning at Gateway High School, 5101 McRee Avenue, a police source said.

Begic, 32, was beaten to death with at least two hammers near Gravois Avenue and Itaska Street about 1:15 a.m. Nov. 30.

One suspect, Robert Joseph Mitchell, 17, who lives on Winnebago Street, has been was charged with first-degree murder and armed criminal action.

It remains unclear whether two other suspects, juveniles 15 and 16, will be charged as adults.

Court documents say members of the group yelled at Begic, his fiancée and two others as they walked to Begic’s car. As the vehicle drove away, one teen jumped on the back and began beating on it. Begic stopped and got out, and one of the men taunted him to fight before all four attacked — and continued to beat him after he fell to the ground.