A 48-year-old Arkansas man serving a life sentence for the 2018 murder of his wife has confessed toe another murder — the 1991 death of 19-year-old Sabrina Lynn Underwood. Rick Allen Headley pleaded guilty to stabbing his estranged wife, Kirstie Headley, in March 2018 and was sentenced to life without parole. Sabrina Underwood disappeared on …