When a friend mentioned that the growing ATM business was a low-risk investment that required little capital but had the potential for big returns, the idea stuck with McKinney. Vending machines that spit out cash would become his dream investment.
Forgiveness, integrity, kindness and respect. The lessons McKinney cultivated in prison were now the lessons he'd use in business and in life. He began by forgiving Rackauckas, the Orange County district attorney who had put him away.
"I understood that he was just doing his job," McKinney said. "He was doing the job he was given."
McKinney even campaigned for his re-election as district attorney.
"We had an evening where we went out and knocked on a few doors together," Rackauckas said. "You know a California prison is not an easy place to be, and to become the person he is now is surprising to me."
And when he married, McKinney even sent out a wedding invitation to the judge who'd sentenced him.
"Whenever you tell someone about McKinney and the years he spent in prison, and him coming out and embracing people that were responsible for putting him in there -- you can't understand how someone can be that magnanimous," Rawitz said.
In less than three years out of prison, McKinney was making a good living owning and operating several ATM machines in south central Los Angeles, still holding down a day job. But while on vacation in Hawaii, he had another one of those life-changing revelations.
"I was starting to actually understand the business, and what it needed to make it profitable. And, and I realized Hawaii was the perfect environment for that," McKinney said.
It was perfect because of all those tourists, and at the time, not very many ATMs where they could get cash easily.
"I was able to come in and pretty much build my company very fast," he said.
When "20/20" spoke to McKinney in May he said he owned 38 machines throughout the state, making as much as $60,000 a month on ATM service fees alone. He said he was the second largest ATM operator on the Hawaiian Islands.
But his success came at a price. His marriage failed, he's struggled with alcohol and he has been taken advantage of by some of the very people he tried to help.
But he doesn't regret giving, because, he said, "When you're willing to give of yourself, when you're willing to be there for someone else, it comes back to you in many different forms."
Giving and forgiving: the mark of a man who has refused to let the past imprison him and in turn has reaped rewards far greater than he ever imagined.
"At times I pinch myself because it seems so unusual," McKinney said. "But at other times I am just like, 'OK, this is where I am supposed to be.'"
The Associated Press contributed to this report.