Upheaval continues to mount for Bill Belichick at North Carolina. His son, Steve Belichick, will resign as the team’s defensive coordinator effective Oct. 27, when his medical leave ends, the school announced Thursday as it said it concluded a probe into the program’s culture. The 39-year-old, a longtime assistant for his dad with the Patriots, has been on medical leave since Aug. 6. He was embroiled in an investigation in which lawyers have been questioning people about whether he used drugs while at work, or gave drugs to at least one player, WRAL reported earlier this month. The investigation also...