Very few TV shows manage to make a real impact on the world, but there's no denying that America's Most Wanted did.
For more than 25 seasons, host John Walsh shared stories about our country's most dangerous fugitives, urging viewers with helpful information to call a special hotline.
Tips from the show's viewers helped catch more than 1,000 criminals, including over a dozen from the FBI's Most Wanted list.
But very few of the show's fans realized that Walsh was trying to solve a murder case in his own family, a cold case that baffled police for decades.
The story begins in 1981, at a department store in Hollywood, Florida, where Walsh's wife, Revé, and their six-year-old son, Adam, were shopping.
Revé took her eyes off Adam for just a few moments to look in a different aisle, and when she returned the boy was gone.
Police were called, teams of men with dogs searched the area, and even a helicopter looked for signs of Adam, but he had vanished without a trace.
It was two weeks before Adam's remains - only a severed head - were found in a nearby canal.
The case was heartbreaking, and it drew national attention. But even though there were no leads on Adam's killer, Walsh and his wife were determined to get justice for their little boy.
Just days after his funeral, they began campaigning to change the way police investigate missing children's cases.
Their efforts led to the passing of the Missing Children's Act and the founding of the National Center for Missing and Exploited Children, which introduced the famous missing children ads on the sides of milk cartons.
The couple became associated with unsolved crimes and the hunt for missing children, which is why Walsh was picked to host America's Most Wanted in 1988.
The show became just another part of Walsh's search for justice, but he admits that interviewing parents with their own missing and murdered children was hard for him.
"I'll always be the parent of a murdered child," Walsh explained in a Nightline interview in 2009.
"Adam will always be in my mind. Your heart is broken. It doesn't matter if it was six months ago or 27 years ago. Your heart is broken. People deal with it differently. Some descend into hell in different ways and you live in that hell."
But after decades of waiting and praying, Walsh and his wife finally received the justice they had been praying for.