In a case with potentially far-reaching press freedom implications, a federal judge in Washington is weighing whether to hold in contempt a veteran journalist who has refused to identify her sources for stories about a Chinese American scientist who was investigated by the FBI but never charged. The judge previously ordered former Fox News reporter Catherine Herridge, who now works at CBS, to be interviewed under oath about her sources for a series of stories about Yanping Chen. Chen, who was investigated for years on suspicions she may have lied on immigration forms related to work on a Chinese astronaut…