20/20

At age 24, British model Katie Piper seemed to have it all, stunning beauty, a non-stop social life and a growing career as a print and television personality in England. But in a shocking moment filmed entirely by security cameras on a busy London street, Katie was doused with sulfuric acid by a complete stranger. Her face and body were badly burned, and any hope of continuing her life as a model was over. Worse, Katie suspected that the attack had been orchestrated by a new boyfriend. But why would someone do this?

Andrew Young, a former longtime aide and trusted friend of Senator John Edwards, sat down for an exclusive interview with ABC News correspondent Bob Woodruff regarding his upcoming memoir, The Politician: An Insider Account of John Edwards's Pursuit of the Presidency and the Scandal that Brought Him Down. In his interview with Woodruff, Young chronicles his time with Senator Edwards, including his efforts to hide the secret that would eventually shock the American public.

Barbara Walters interviews South Carolina's First Lady Jenny Sanford in conjunction with her memoir, Staying True," which will be published in February. Sanford discusses how she tried to stay true to herself and her family after husband Governor Mark Sanford disappeared and then revealed his extramarital affair with an Argentinean woman, the heartbreak behind the headlines of their marriage breakup, and being a political spouse.

It seemed like a neighborhood right out of the 1950's, where adults kept an eye out for trouble and children walked home from school every day without fear. Until one day last October, when 7-year-old Somer Thompson seemed to vanish into thin air on a crowded sidewalk -- in broad daylight -- less than a mile from her home. Her body was discovered two days later in a landfill in Georgia, and the community was shocked to learn that there were 162 known sex offenders and predators living amongst them within a five mile radius of Somer's elementary school.

On Friday evening, 20/20 co-anchor Elizabeth Vargas will have an intimate and jaw-dropping report on mothers who are struggling to stay alive, battling their alcohol addiction before it's too late. The in-depth hour profiles the stories of four women from across the country who open up with startling honesty about their battle with the bottle.

The only thing possibly worse than losing loved ones in a fire would be if you were falsely accused of setting the blaze. Yet that's what some experts say happens around the country when the wrong fire investigator determines arson based on outdated techniques. Is it what happened to Amanda Kelly? Kelly's world fell apart on a winter's day in 2001 when she was charged with arson, accused of setting a fire that engulfed her Alexandria, Louisiana home, killing her three children. She faced the death penalty.

Becky Babcock: My Mother Was a Killer. Daughter of Diane Downs, given up for adoption, talks about uncovering the secret of her mom's identity.

Is it ever okay to take the law into your own hands? That question has divided a California community since the murder of a respected town businessman last February. Aaron Vargas, a young father about to be married, shot and killed Darrell McNeill - a former neighbor and the father of his childhood best friend - while McNeill's wife watched. But as the story unfolded, everyone in Fort Bragg, CA was stunned to learn of the alleged dark secrets kept for decades between the two men. Vargas told his family and the authorities that McNeill had sexually and psychologically abused him for years. Was killing McNeill revenge? Vigilante justice?

How young is too young... Should parents just say no to kids who want to do something so extreme and dangerous as climbing Mt. Everest, bullfighting or sailing solo around the world? Is a seven-year-old too young to hate? Is a 10-year-old plagued with psychiatric disorders too young to use medical marijuana?

A mystery woman who says she was a first love and longtime confidante of Joran van der Sloot is speaking out for the first time.

It has been a year since Michael Jackson's death and now, only on 20/20, what no one has yet heard, new intimate details from those who stood by his side right to the end.

Was the untimely death of a Baptist preacher's wife really a suicide as the justice of the peace first ruled or was Kari Baker, a perfectly healthy mother of two, murdered by her husband? Kari's family's persistence in keeping the case alive, finding another woman and suspecting foul play, ultimately led to her husband Matt's arrest, and then conviction.

Did an attractive yoga teacher from Maine try to kill her husband by beating him with a baseball bat as he slept, then shoot herself in a staged home invasion? Jim Avila reports on the heinous crime that stunned a small Maine community, and the trial of Linda Dolloff.

Washington Redskins Cheerleader Ambassador Desiree Jennings, 25, had everything going for her until one day her body suddenly stopped working, turning into a twisted, jerky mess. For some inexplicable reason, when she runs, Desiree's body untwists and straightens out, and sometimes she can walk backwards and sideways without trouble. Footage of this unusual phenomenon spread quickly online, making her an internet sensation. Was it caused by a flu shot, as Desiree thought? Her journey for answers to this medical mystery takes her to a controversial osteopath in North Carolina and ultimately leads people to question whether or not her affliction is real.

How can a person living a life many can only dream of suddenly become a cold blooded murderer? Kelley Cannon was an attractive, well-to-do debutante who lived in a grand house with beautiful kids and a loving attorney husband. But after a back injury left her abusing drugs and spending time in rehab, her world started to fall apart. First her husband, James, filed for divorce, than he won temporary custody of their four young children. After James was found dead in a closet, strangled to death by a phone charger cord, all eyes turned to Kelley. Was this once petite woman capable of killing a man -- the man she once loved - with nothing more than a phone cord?

A man who lost 400 pounds and gained a new life, a bald model who wins beauty pageants, a man with an idea that catapulted his financial worth into the stratosphere, a wife who stunned her neighbors -- and her husband -- when she fell in love with another woman.

The question of who murdered a Fayetteville, North Carolina military wife and two of her young daughters in their own home, leaving only one toddler alive, seemed to be answered with the conviction of a soldier who was a husband and a father himself. But years later that verdict was overturned and the original suspect, Tim Hennis, was acquitted. Then, after two decades of freedom, dramatic new evidence points back to Hennis. Elizabeth Vargas reports on a murder mystery that played out over 25 years... and came to a surprise ending in a North Carolina courtroom this past April.

Chris Cuomo's Exclusive Television Interview with Bobbi Ann Finley, Who Allegedly Targeted More than a Dozen Servicemen by Marrying Them and Taking off with Their Money.

In an ABC News investigation, Brian Ross tracks down the American fugitives accused of being part of a scam that has affected thousands of senior citizens. US officials say the swindlers, based offshore, have used new technology and the good name of the Make-a-Wish Foundation to rip off millions of dollars from unsuspecting Americans.

Whom to believe -- mother or son? Just hours after the drowning death of seven-year-old Adrianna Hutto, her six-year-old brother, AJ, had a horrific story to tell police about their mother, Amanda Lewis. He accused his mother of dunking Adrianna, drowning her in their Florida pool. But can AJ be believed, or was he coached into telling the damaging story?