A 16-year-old boy was arrested in a shooting at WestFest in West Valley City that killed three people. The victims include an 8-month-old baby, a 41-year-old woman and an 18-year-old man.

West Valley City is Utah’s second-largest city, after Salt Lake City, with a population of about 145,000 people. The fatal shooting came a day after a bystander was killed at a “No Kings ...