"The whole point of the program," Harris said, "is that these people would be able to obtain and hold down lawful employment, and if they're undocumented, they probably would not be able to do that, so it would go against the very spirit of the program" to continue admitting them.
Harris, 44, was elected district attorney in 2003 and reelected in 2007. She designed Back on Track to help young adults who are arrested once for selling drugs; the goal is to help them avoid falling into a life of crime. Like cities and counties across the nation, San Francisco was already running several programs with that goal.
Back on Track participants agree to plead guilty to a drug felony and spend a year in the program, a mix of community service, employment and life-skills training, family counseling and English lessons for those who need them. While in the program, they are free to live where they wish.
Even natural adversaries of the district attorney have applauded Back on Track.
"It's very innovative for the district attorney to have a program like this," said Simin Shamji, a deputy public defender in San Francisco. It might work better, she said, if the D.A.'s office ceded some control and collaborated more with social service agencies.
Over the last four years, 113 admitted drug dealers have graduated from the program, while 99 were yanked for failing to meet the requirements and sentenced under their guilty plea, according to the D.A.'s office.
Harris said graduates of the program are far less likely than other offenders to commit crimes again, but her spokeswoman declined to provide detailed statistics.
In her campaign for attorney general, Harris calls Back on Track a model for a statewide approach to preventing crime and easing prison overcrowding.
The campaign has consumed much of Harris' time in recent months. Last week, she was raising money at homes in Calabasas, Studio City, Pacific Palisades and Hollywood.
Harris' liberal San Francisco pedigree will pose challenges in a statewide race, particularly her 2004 vow to "never charge the death penalty." That pledge will be put to the test in the upcoming murder trial of Ramos, the illegal immigrant accused in the shooting deaths of a man and his two sons. Harris has not announced whether she will seek the death penalty.
Now, the Izaguirre case adds a new complication to her campaign.
"The immigration issue, as it relates to the Izaguirre case, obviously is a huge kind of pimple on the face of this program," Harris acknowledged. An instant later, she regretted the metaphor, saying, "I don't mean to trivialize it, nor do I mean to cover it up."
Handcuffed and wearing an orange jail uniform, Izaguirre appeared Wednesday in a San Francisco courtroom. He told a judge he would plead guilty to robbery for the July 2008 purse-snatchings. But for reasons that were left unclear, he then abruptly withdrew the plea and backed out of a deal with prosecutors that would have put him in prison for three years and four months. His trial is set to begin Sept. 4 and he could be deported afterward.
"He is being prosecuted, and he will be deported with my full encouragement and support," Harris said.
Kiefer, who packages medical devices for a living, said she has left California for good, in part because of the trauma of nearly having been killed on her way to dinner last summer in Pacific Heights. Nearly a year later, she remains baffled that San Francisco authorities ever let Izaguirre and other illegal immigrant felons back onto the streets.
"If they're committing crimes," she said, "I think there's something wrong that they're not being deported."