An alleged "murder dentist" in Colorado. Hawaii husband takes the stand at his second murder trial. And Keith talks about his latest podcast series.

Listen to this week's episode of the Dateline: True Crime Weekly podcast with guest host, Blayne Alexander. A dentist already facing murder charges for allegedly poisoning his wife is back in court. This time he's accused of plotting to murder four other people from behind bars. In Honolulu, a man…