Is the clue to finding a killer in the diary of a 15-year-old girl?

By the time Kennedy cousin Michael Skakel was convicted of the murder of his neighbor Martha Moxley in 2002, more than quarter of a century had gone by since Martha's bludgeoned body was discovered under a tree on the Moxley property.

"It was devastating. You have no peace. You've lost it all," Martha's childhood friend Tori Holland told "48 Hours" correspondent Erin Moriarty in "The Diary of Martha Moxley," airing Saturday, November 6 at 10/9c on CBS and Paramount+.

On the eve of Halloween in 1975, when Martha didn't return home from a night out in the neighborhood, her mother Dorthy alerted the police and began calling Martha's friends.