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Friday, Aug. 14: A drug sting goes awry and a cold case solved

It sounds like a plot from the movies: A young woman goes undercover to help police in a secret drug sting -- unaware of the dangers that lie ahead. But this story was no movie,and there was no Hollywood ending. This young woman suddenly found herself alone, on a dead-end road, staring down the barrel of a gun. It was the last time anyone would see her alive. And now her heartbroken family is asking: Where were the police? NBC's Chris Hansen investigates "Deadly Dealing."

Also: Nearly 25 years ago, a smart, loving, little boy disappeared, his body found a couple of weeks later. Now the case is solved. But what took so long? As you'll see, it was plagued by missed opportunities, shaky witnesses, and an investigation that went nowhere. With all that, the truth might never have come out at all. But the moment you meet the boy's mother, you'll understand why it finally did. NBC's Hoda Kotb reports on what really happened "Down By the River."

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