Letha L. Sparks

Age: 75
Home state: Texas
Cause: Exposing investment scams

Sparks, an accounting major who finished college at age 41, found she had a passion for uncovering fraud. Since 1998 she has pursued scammers, seeking out suspects undercover by posing as an investor. In 2009 she analyzed thousands of documents relating to an investment scheme involving life insurance. In mere days, she found evidence that enabled a speedy shutdown and the return of nearly 70% of investors' money — an unusually big recovery. As a forensic accountant at the Texas State Securities Board, she has helped expose over $750 million worth of rip-offs targeting more than 4,000 people.

Says Sparks:

"Little by little, I can whittle away at the con man and make a difference. I can make sure justice prevails."