Gailen Lopton was in a downtown alley two weeks ago, having a buddy jab him in the neck with a heroin-filled syringe, when he suddenly found himself in the company of Seattle's finest.

The police officers weren't looking to lock him up, though. Instead, they offered him a chance to enroll in a first-of-its-kind program called Law Enforcement Assisted Diversion, aimed at keeping low-level drug offenders and prostitutes out of jail — and in housing, counseling, job training or whatever other services they need. Unlike with many drug courts or other programs, participants aren't threatened with jail time or with being kicked out if they relapse.

Lopton, 24, jumped at the chance.

"Over the past six months, people have been talking about it, about how they got into treatment because of LEAD, how they got a new apartment because of LEAD," he said Tuesday as he loitered outside a payday lending store. "If it's something to help me get off the streets, to help me make better steps to a better future, I'm down — I'm so down."

More than three years after police, prosecutors, defense attorneys, elected officials and community groups launched the pilot program, a University of Washington study released Wednesday shows encouraging signs of its effectiveness. Participants were up to 60 percent less likely to be arrested within six months of enrolling in the program than a control group, the evaluation found.

The results are so encouraging that advocates say it should prompt reconsideration of President Barack Obama's call for an expansion of drug court programs and a hard look at replicating Seattle's effort nationwide.

The analysis comes as communities around the country seek alternatives to the revolving-door criminal justice of the drug war. Santa Fe, New Mexico, launched a program modeled on Seattle's a year ago, and Albany, New York, plans to start its version next year. Dozens of other cities, including San Francisco, Atlanta, Houston and Portland, Maine, have expressed interest, and one of the backers of Seattle's effort, billionaire George Soros' Open Society Foundations, announced last week that it would give five jurisdictions grants of $150,000 to help them copy it.

"This is a big deal — bigger reductions than are seen in almost any criminal justice interventions," Lisa Daugaard, policy director at King County's Public Defender Association, wrote in an email. "This makes the case for 'system as usual' processing (even with drug courts) very weak."

In Seattle, which has also led the way in providing housing where chronic alcoholics can drink, saving millions on emergency response and hospital costs, the LEAD program was started with money from private foundations. Open Society Foundations, the Ford Foundation and others provided a budget of $800,000 a year for four years. The city matched the annual contributions over the past two years. A cost-benefit analysis is due out later this spring.

"Now that we know it works, I think the interest in this is going to just explode," said Gabriel Sayegh, managing director of policy and campaigns at the New York-based Drug Policy Alliance, which is also affiliated with Soros. "Seattle is a model for these other places, many of which are incredibly hungry for solutions that work."