we need to find out who did this. did it feel like you are lifting the lid on something much bigger? it s even worse than i thought it was. what they were hiding, what they knew. hello and welcome to dateline. four year old barbara jean horn was abducted while playing near her philadelphia home. her body was discovered within hours. police immediately launched a hunt for her killer. but years passed before a suspect confessed. even then, the case was far from over. decades later, an investigation would reveal abuses of power. deep inside philadelphia s legal system. from the homicide unit, to the prosecutor s office. here is lester holt with the investigation! when sharon was 21 years old, she lived in northeast philadelphia. and worked at a department store. but her greatest shame was to have a daughter. i only had a girl s name picked out. it s all i ever wanted. was children. shortly before sharon gave birth, john entered her life. and he became barbara