The makings of a great story can be found anywhere. Just ask reporter Marshall Allen who recently took a telemarketing call and developed it into his first investigative piece for ProPublica.

The phone call had come from a company called Heart Check America that was hoping to convince Allen and his wife to sit through a presentation in exchange for two free heart scans worth $800.

"I knew immediately when I got the call that it was a story, so I just started taking notes," Allen says. "And I'd ask if there were risks associated with this procedure. They said it was 'risk free,' and I knew that was not true. They should be disclosing things, not just glossing over the facts. It was clearly a one-sided conversation meant to sway me. It was not a presentation that had intellectual integrity."

Allen eventually found that Heart Check America was using overly aggressive marketing tactics and had received numerous complaints from consumer groups. He used that information and developed it into a story. Poynter's Al Tomkins shares all of the details on how the piece came together in this post.