For two years, Stacey Wales kept a running list of everything she would say at the sentencing hearing for the man who killed her brother in a road rage incident in Chandler, Ariz. But when she finally sat down to write her statement, Wales was stuck. She struggled to find the right words, but one voice was clear: her brother's. "I couldn't help hear his voice in my head of what he would say," Wales told NPR. That's when the idea came to her: to use artificial intelligence to generate a video of how her late brother, Christopher Pelkey, would...