The Girl Who Knew Too Much Forty Eight Hours : Season 23 Episode 19

More than 17 years have passed since Scott County, Mo., Deputy Sheriff Rick Walter pulled over on a desolate strip of highway in Benton, Mo., to examine what he thought was an abandoned car. Instead, he discovered the body of 19-year-old Angela Mischelle Lawless. Based on the blood evidence, investigators believed Mischelle, who may have been running for her life, was brutally beaten and then placed back in her car, where she was shot three times. As Walter was working the crime scene, a local man reported that he had seen the young woman in her car, and also told investigators that he saw a white car driving near the crime scene. At the same time, authorities immediately looked at Lawless' boyfriend, but could find nothing to tie him to the crime, and he passed a polygraph. Weeks went by with few leads, until four months later investigators got a break. As Sheriff Walter tells "48 Hours" correspondent Erin Moriarty, "Everyone is scared about this case."