A 16-year-old reputed gang member was arrested Thursday in the execution-style slayings of three rivals shot to death at a Hollywood gas station in what police said was one of the most bloody gang-related attacks seen in the area.

"This is the most violent gang-related homicide on the west side in the last 10 years, as far as the number of people killed," Lt. Brad Merritt said in announcing the arrest."He virtually assassinated" the victims, Merritt said of the suspect.

The youth, a Hollywood area gang member, was arrested around 3:30 p.m. about a block from the crime scene as he was driving away from his father's residence.