There is no known motive for why 52-year-old married father of two, Matthew Mitchell, would shoot and kill his wife and children this week, and then turn the gun on himself. The Mitchells were prominent Houston restaurateurs who spent the last several years building their business, appearing in magazines and on local tv together. Just 10 days before her death, Thy Mitchell posted a now eerie video with her husband, smiling and joking about growing old together.