The three Louisiana churches went up in flames in a span of 10 days, each doused in gasoline and torched with oily shop rags in the middle of the night. Each Baptist congregation was predominantly black, causing church leaders to fear that white supremacists may target their parish next. But as the fears swirled, the arsonist, 22-year-old Holden Matthews, was busy planning his next album cover, according to text messages obtained by prosecutors He burned down the three churches in St. Landry Parish, federal prosecutors said Monday, because he wanted “to raise his profile as a ‘Black Metal’ musician.” Matthews,...