Williams said the program - TCY for short - will take about 75 people a year who are willing to change their lives, and give them education and job training backed by social services and other support.
It was the second chance for education and career that sold Soto: "I wasn't really interested in the beginning, but after they told me they would help me get a job, improve myself, I decided to take a chance."
Soto and the others had just completed the four-week intensive orientation to improve their verbal and math skills, and teach them practical job skills that Williams described as cleaned up, dressing right, and "showing up."
Two arrived early for the news conference, Williams noted.
Soto said the orientation raised his reading skills from ninth-grade level to 12th, and math from eighth-grade level to 11th.
TCY participants will be guided into educational or job-training programs and trade apprenticeships. They will also become mentors to the next incoming TCY class.
If Soto and the others successfully complete what is planned as a one-year program, they will plead no-contest to the charges pending against them and their criminal records will be expunged.
But, turning to face the eight, Williams emphasized that "the choice is yours," and added that those who are rearrested will be treated like any other criminal defendant.
Williams acknowledged that the program - a 2009 campaign pledge - is politically risky. But if it works like San Francisco's "Back on Track" program that Williams looked at, Philadelphia would see a significant drop in the number of people rearrested and a reduced crime rate.
And that's not counting millions in taxpayer money that would be saved by not incarcerating hundreds of nonviolent felony drug offenders.
Williams said current data show that 73 percent of Philadelphians convicted of a crime will be rearrested within two years. Regardless of politics, Williams said, "what we're doing now does not work."
"We've been trying to incarcerate our way out of crime," Williams said.
Charles A. Cunningham, the city's first assistant public defender, whose agency is a TCY partner, said such programs "are really the way we're going to fight the war on drugs, the war on crime."
"This is money well-spent and you will be saving lives, many lives," Cunningham added.
In San Francisco, District Attorney Kamala Harris - now California attorney general - created Back on Track in 2009. Despite a rough start, the program has been credited with reducing San Francisco's recidivism rate for participants to 10 percent compared with the 54 percent rate of other offenders.
Williams said TCY would cost $1 million a year to serve about 200 eligible participants - $7 million less than if the same people were behind bars.
The Lenfest Foundation kicked in $1 million and William Penn $300,000; no city tax money is being used for the pilot, Williams said. If the program is successful, Williams said, he hopes to generate future funding through grants.
A broad coalition of agencies will participate, including the Philadelphia court system, the Defender Association of Philadelphia, the Center for Literacy, and the Pennsylvania Prison Society.
Case management, training, and placement will be managed by the Philadelphia-based JEVS Human Services. To ensure reliable data on how well the program performs, the national firm Public/Private Ventures will monitor and assess TCY's implementation.
City Councilman Curtis Jones Jr., chairman of Council's Public Safety Committee, said he liked that TCY offers education and job-training.
"Everybody isn't going to college," Jones said, "and you can make an honest day's pay with your hands."
Soto, who said he wants to enroll in community college and would like to become a police officer, acknowledged that street life can be tempting.
"Somewhat," Soto said. "But I see what my friends are doing and I tell them it's just not worth it. Trust me, I got caught."
Contact Joseph A. Slobodzian at 215-854-2985 or firstname.lastname@example.org, or follow on Twitter @joeslobo.