A gunman killed a social media influencer during a live stream in Mexico’s volatile northwestern state of Sinaloa, authorities said on Wednesday, a public killing that underscored ongoing violence targeting social media personalities in the Latin American nation. The influencer, Cesar Gastelum, was killed on Tuesday night in the Sinaloa state capital of Culiacan, officials said. Mexican authorities implied the killing of the young man was linked to cartel violence but did not blame any...