The first three and a half seasons of the hit TV series "Pretty Little Liars" are built on finding the answer to one question: Who killed Alison DiLaurentis? When Alison went missing the summer ...

Mystery–thriller series Pretty Little Liars (PLL) premiered on ABC Family ... the disappearance of their clique’s leader, Alison DiLaurentis (Sasha Pieterse). The four remaining friends ...