In 1992, 19-year-old Mischelle Lawless' bloodied body was found in an abandoned car on a desolate strip of highway in Benton, Missouri. Four months into the investigation, investigators got a break: 17-year-old Joshua Kezer had been held briefly in the county jail on assault charges, where, according to several inmates, he confessed to killing Lawless. Kezer was convicted and sentenced to 60 years in prison. Sheriff Rick Walter re-opened the case in 2005. Judge Richard Callahan agreed to review the case and, citing prosecutorial misconduct and a lack of evidence, declared Josh Kezer an innocent man. But someone killed Mischelle and high on the list of suspects is a local man, Mark Abbott, who was once a star witness for the prosecution. “48 Hours" correspondent Erin Moriarty reports. This classic "48 Hours" episode last aired on 7/21/2012. Watch all-new episodes of “48 Hours” on Saturdays, and stream on demand on Paramount+.