Source: AP Betty Broderick, who was convicted of second-degree murder for the killing of her ex-husband and his new wife in 1989, has passed away of natural causes at the age of 78.  Broderick's case became a national sensation when details of her marriage and messy divorce from her ex-husband, Dan Broderick, came to light. The two were originally married in 1969 and went on to have four children. Betty worked and supported her family while Dan went to medical school and then law school, eventually becoming a successful medical malpractice attorney. In the early 1980s, Dan began an affair with Linda Kolkena, who was his legal assistant. Betty grew suspicious and erratic, with Dan eventually filing for divorce in 1985. Dan and Linda married quickly after the divorce was settled, and Betty moved to a new home with the pair's children.  Betty continued to harass Dan and Linda, breaking into their home and leaving threatening voicemails on their answering machine. Betty was jailed...