By Amy Costello

When Mark Goldsmith was asked to volunteer as principal for a day in a New York school, he asked to go to a tough school. He ended up visiting Horizon Academy at Rikers Island, a prison, where he found he had a knack for talking to inmates.

That volunteer experience transformed the retired cosmetics executive, who went on to found a nonprofit that has helped many young men leaving prison learn to build successful lives and stay out of jail. About 80 percent of his group's clients keep out of legal trouble, a far better record than the 43 percent of young men who typically land back in jail for a second time.

In this edition of Tiny Spark, Amy Costello asks Mark Goldsmith whether volunteers should worry that some people are just too troubled to try to help. They also discuss how Mr. Goldsmith's skill and experience helped him change the lives of others.

This is the second episode of Tiny Spark, a new podcast sponsored by The Chronicle, that features people in the business of doing good. Listen to Exposing Corruption in International Adoption, the first edition of the podcast.

Amy Costello has reported in Africa for National Public Radio, PBS television, and the BBC World Service. Her Frontline story, "Sudan: The Quick and the Terrible" was nominated for an Emmy Award. Amy now lives in New York where she has worked as an adjunct professor at the Columbia University Graduate School of Journalism.