All Things Considered

In California in the early 1980s, a cracked tooth sent Mike Williams to the dentist's office.

When Williams asked to see the tooth, the dentist said he had a mirror but that there was no camera or anything to show people the insides of their mouths. So, Williams invented one: the first intraoral camera.

His invention was a big success, and it led to other medical technology ventures that made him millions of dollars. Williams' career as an inventor and entrepreneur took off, but it wouldn't last.

In 1962, a grisly double murder on a deserted stretch of desert rocked a small community outside Phoenix.

A young couple had been shot to death in a case that stumped Maricopa County investigators. Then, something happened that should have cracked it wide open: A man named Ernest Valenzuela confessed to the crime. But police didn't pursue the lead, just one misstep in an investigation and eventual trial that were rife with irregularities.

In the early 2000s, the get-rich-quick scheme of choice for young college dropouts was poker — and not your grandfather's poker, with clinking chips on green felt tables. Online poker. For a few years it was a national obsession for a generation of young men who grew up playing hours and hours of video games.

Many of these players couldn't get into casinos because they were underage, but they used their brains and introductory statistics courses to rake in millions, often playing 10 or more games simultaneously on huge computer monitors.