A heart donated by a Marine who survived two tours in Iraq and was killed by a stray bullet back home has saved a former Marine's life. Ricky Martinez Jr. was killed in Chicago in 2006 by a stray bullet fired by a gang member while he was on his way home from a Cubs game, shortly after returning from the battlefield.

The heart was donated and reached a former Marine, Brian Troy. He got the chance to meet the parents of the man who saved his life, Ricardo Martinez and Adalila Cruz. During a press conference Saturday, they promoted organ donation along Secretary of State Jesse White.

"When you can give someone a second chance at life like Ricky Martinez, then of course, you fall into the category of being a hero," White said.

"The first year we didn't try to find out, with all the pain and grieving," the slain Marine's mother said. "But it got to the point where I thought, 'What's done is done, I want to meet the person who has my son's heart.'"

Martinez was just 23 when he was shot, mistaken on April 24 2006 for a rival gang member. It was sheer luck that his parents got a chance to meet the organ recipient. This only happened because the former Marine, 43-year-old Brian Troy, and Martinez' parents have contacted the Gift of Hope organ donor network. While the organization normally does not share contact information, but made an exception due to the unusual circumstances.

Troy and his wife, Denise said that his life changed after the transplant. Troy apparently has displayed some of the alleged "transplant memory," which means that he started to display some physical and mental traits of the donor. For example, black hair grew on his chest where blonde hair was shaved before the surgery. He also started craving nachos, one of Ricky Martinez's favorite snacks.

The first heart transplant on a human occurred in 1964 by a team led by Dr. James Hardy, involving a chimpanzee heart.The first human to human heart transplant was performed three years later. Currently, there are more than 5,000 people waiting for an organ that could save their lives.