JOSHUA CASTILLO got off on a technicality.

The 29-year-old homeless Portlander was acquitted earlier this month, after insisting on a trial for charges stemming from his encampment beneath a Southeast Portland overpass.

Prosecutors argued Castillo's makeshift shelter was a violation of Portland's laws against "erecting structures." And that the fact Castillo had set up the shelter after cops had told him, the week before, that such conduct was illegal made him guilty of "interfering with a peace officer" (IPO), a misdemeanor charge police and prosecutors have used to add heft to cases against campers this year ["Can't Sleep Here," News, July 30].

But the officers who cited Castillo had made a mistake, Multnomah County Circuit Judge Cheryl Albrecht found. They hadn't explicitly documented whether Castillo's shelter had been up for more than two hours, as required under the structures law.

"While it may be reasonable to infer that he could have been there for more than two hours," Albrecht said at the December 8 trial, "I would have to speculate."

Since the state couldn't prove beyond a reasonable doubt Castillo had done anything wrong, the charges went away.

It was, all things considered, a relatively mundane finding on relatively minor charges. Yet the ruling held great interest for a segment of Portland's publicly funded defense attorneys—who have found themselves representing more and more clients like Castillo this year.

Those public defenders are raring for a fight over Portland's enforcement of its anti-camping laws. And round one is scheduled for next year.

In a wide-ranging motion filed earlier this month, attorneys from the county's largest public defense firm are seeking to dismantle Portland's camping ban by arguing it violates both the Oregon and US Constitutions. The Multnomah County District Attorney's office is taking the matter seriously, requesting six weeks to respond to those arguments. And the case will be decided by a judge with a track record of curbing the city's enforcement excesses: Circuit Court Judge Stephen Bushong, who ruled Portland's "sit-lie" law unconstitutional in 2009.

The oft-debated camping ban is, in short, about to get a test.

"It's something a lot of us in the public defense community have been thinking about, just how to go about attacking that," says Sara Mulroy, one of the public defenders who filed the motion. Mulroy and other attorneys have been disturbed, she says, to see homeless clients slapped with arrests and misdemeanors because they don't have a place to stay.

"I'm seeing this with my poorest, most vulnerable, voiceless sorts of clients," Mulroy says. "This [motion] is a starting point."

The setting for the upcoming fight is the case of Alexandra Barrett, a 25-year-old homeless Portlander who's amassed 17 citations for camping-related offenses since May. (The Mercury previously wrote about Barrett after a Portland police officer arrested her for spitting on the sidewalk ["You Can Be Arrested for Spitting," News, October 8].)

Again and again, Barrett has been arrested and charged not only for camping on public property (mostly Chapman Square, downtown), but also for interfering with a peace officer after she'd been warned not to camp. It's a case similar to others that have been filed against the homeless this year, except in one key area: Barrett wants to fight the charges.

"That doesn't always happen with these kinds of cases," Mulroy says.

So the firm Metropolitan Public Defender Services, which has assigned a volunteer attorney to work on camping enforcement cases full time, is using Barrett's case as an opportunity.

The motion to dismiss the charges against Barrett, filed December 4, goes beyond the specifics of her case, arguing that Portland's law is fundamentally unfair to all homeless Portlanders.

"For people who are homeless, who carry all their possessions, and who do not have shelter to go to every night, whenever they set up a sleeping bag to bed down in the confines of Portland, they are in violation of the ordinance," the motion says. "Because the ordinance criminalizes conduct that is necessary for homeless individuals to simply live, it criminalizes status and is unconstitutional."

The city's current enforcement stratagem for homeless encampments—enshrined in something called the "Neighborhood Livability Improvement Project"—looks like this: Police officers, upon finding homeless campers, warn them what they're doing is illegal, and give them a booklet detailing available social services. Then, if they're spotted camping again, cops can make an arrest for "interfering."

But the motion points out that handing out a booklet isn't enough. There are more homeless people in Portland than available shelter beds, so knowing about a service isn't always enough to get people off the streets immediately.

"Simply directing Ms. Barrett to a shelter is not an answer," the document states.

The argument might seem like a long shot. It's not the first attack launched on Portland's camping ban, after all—and past challenges to the law have fallen short of the sweeping changes attorneys hoped for.

But it turns out there's also precedent for this line of reasoning. In 2000, Multnomah County Judge Stephen Gallagher considered the case of two men charged for sleeping in their camper on a residential street. In a strongly worded ruling, Gallagher found Portland's camping ban was unconstitutional for the exact reasons being offered in Barrett's case.

"There are a great number of alternatives regarding housing, job training, mental health services, etc., that should be put in place to both minimize the effect of homelessness, and eliminate homelessness altogether," Gallagher wrote, "before our city resorts to arresting individuals for sleeping and eating in the only locations available to them."

What did the city do in light of the judge's rebuke? Not much.

"I know everyone was really excited about it at the time," says Monica Goracke, an attorney with the Oregon Law Center who frequently represents homeless defendants. "And pretty much right away it was clear that the city decided not to do anything."

The city doesn't technically have to follow the guidance of one judge on the circuit court level. An appeals court would have more weight, but Gallagher's ruling was never scrutinized at that level.

"This is just one decision of one judge," former City Attorney Jim Van Dyke, then a deputy city attorney, told the Oregonian at the time. "We've had other decisions of other judges upholding that ordinance."

If Bushong, like Gallagher, agrees the camping ban is problematic, it's possible the result could be similar. But the city has also chosen to be responsive to such rulings in the past.

When Bushong ruled sit-lie was unconstitutional in 2009, Portland officials immediately took action to end its enforcement. That move, some say, was informed by the politics of the time.

"Of course we're taking it seriously," says Chuck Sparks, a chief deputy in the district attorney's office. But he notes: "One judicial ruling does not control everything in the jurisdiction."