Democrat Larry Krasner, the front-runner to become Philadelphia's next district attorney, says he supports city-sanctioned spaces where people addicted to heroin can inject drugs under medical supervision and access treatment, a move advocates see as a promising step toward making the city the first in the U.S. to open such a site.

His Republican opponent, Beth Grossman, says she's open to discussions on the matter.

For those on the front lines of the heroin crisis in Philadelphia, both are encouraging stances in a political arena where the idea can still be dismissed out of hand. But recently, cities across the country have begun to consider the possibility of instituting supervised injection sites; several nations, including Canada, have used the approach for years.

These sites are as widely supported by medical experts as they are controversial among the general public and, typically, elected officials.

Pennsylvania Attorney General Josh Shapiro, who has spoken frequently about addiction as a medical issue, has not supported them. The interim report from President Trump's commission to combat addiction, chaired by Gov. Christie, does not mention the idea. Consideration of a supervised injection site was the most controversial of 18 recommendations in Mayor Kenney's opioid task force report in May. A status update on the full report, released late Wednesday by the departments of public health and behavioral health, whose commissioners co-chaired the task force, said "exploration" of the notion was in the "planning" stage.

But Krasner says he faced similar opposition when he took the needle-exchange program Prevention Point on as a client in the early 1990s. He said a safe injection site, like a needle exchange, is just one tactic in combating an addiction crisis that must be treated as a medical issue. In a statement released this week, he said that if safe injection sites could help stave off that crisis, it's a "moral obligation" to open one in Philadelphia.

"Three die a day in Philadelphia, 13 die a day in Pennsylvania, and nationally, there are 50,000 deaths a year," he said in an interview Thursday. "So, yeah, I'm OK with safe injection sites."

Grossman says she has warmed to the idea, citing articles in the Inquirer and Daily News on librarians who trained themselves to use Narcan to save overdose victims in Kensington, and of elementary-school students witnessing a man injecting heroin into his neck.

"If people are willing to talk about it, it's certainly something that I'm willing to explore," she said.

Both candidates stressed the importance of consulting with residents in neighborhoods like Kensington, where heroin use is heavily concentrated. "If they don't want it, that has to be taken into consideration too," Grossman said. And the legalities of such a site have to be parsed.

"Who the district attorney is, and their opinion on this, is crucial," said Scott Burris, a Temple University professor of public health law. "Safe injection facilities are neither clearly legal nor clearly illegal. A district attorney could ask: 'Do I believe this is a bona fide public health measure and therefore not subject to various kinds of criminal laws? Or do I think this is a criminal enterprise in disguise that I'm going to shut down?' "

Burris said a safe injection site is "good public health," but elected officials exploring the possibility have to work carefully to bring the public on board.

Still, attitudes are shifting, said Devin Reaves, the executive director of Life of Purpose New Jersey, an addiction-treatment center, and a member of Kenney's task force on the opioid crisis. He said he was met with laughter when, years ago, he first began speaking to legislators about making Narcan more widely available, or passing good Samaritan laws that don't penalize drug users who call the police for help.

"And last year, the physician general signed a standing order that made Narcan available over the counter in Pennsylvania," he said. "And we weren't the first state to do it. There are people on the mayor's task force who were opposed to safe injection sites in the beginning whose minds were swayed."

Kenney's spokeswoman, Lauren Hitt, said the city will decide over the next several months whether to "move forward" with a plan for a safe injection site. She said Krasner's announcement hadn't affected that process.

"In making that decision, we're evaluating potential legal challenges, including from the state and federal government, suitable location, cost, security, and how to address neighborhood concerns," she said, and city officials were planning to visit a safe injection site in Canada this fall.

All 18 recommendations from the mayor's opioid task force are somewhere in the "planning" or "implementing" stages, from expanding access to medication-assisted treatment for addiction to creating the ability for emergency rooms to send overdose victims directly to treatment, which currently is blocked by a maze of bureaucratic hurdles.

Meanwhile, various measures show the epidemic of addiction continuing to worsen both here and nationally. Philadelphia emergency medical crews administered the overdose reversal medication naloxone to more than 3,000 people during the first six months of 2017, up more than 75 percent from the same period last year.

And accidental drug-related deaths, which have been steadily increasing for several years, shot up during the last three months of 2016 and continued at the same level or higher early this year, a pace that would end 2017 up 30 percent for the second year in a row. Accidental overdose deaths statewide were up even more: 37 percent in 2016, according to data collected from county coroners throughout Pennsylvania by the local division of the Drug Enforcement Administration. The latest federal data show a 21 percent increase in total drug mortality – a projected 64,000 deaths nationwide — for the 12 months ending Jan. 31.

The increases everywhere were driven largely by a flood of illicit fentanyl, most of which is imported from China and then mixed with heroin, a combination that makes the end product both cheaper and more powerful.