A federal judge in Oregon has found that an immigrant woman's constitutional rights were violated when she was held in jail without probable cause at the request of U.S. immigration authorities, one of several recent federal court decisions to scrutinize the practice of keeping people in jail after they're eligible for release so that they can be considered for deportation.

The rulings make it clear that local officials are not required to honor immigration authorities' requests that someone in custody continue to be held even though their original charges were resolved or they are eligible for bail, and that local jurisdictions may be held liable for doing so.

The rulings have spurred several jurisdictions — from multiple Oregon counties to the city of Philadelphia — to announce they will no longer honor requests for such holds. Previously, some counties and states had already limited use of the practice, arguing it is expensive, erodes immigrants' trust in law enforcement, and drags people with minor infractions such as traffic violations into deportation.

"This will undoubtedly improve the relationship between each of these offices and the immigrant and refugee communities," said Carmen Madrid, an organizer with the Portland-based nonprofit Center for Intercultural Organizing.

The decisions come as immigration reform has stalled and the Obama administration is being criticized for deporting mostly people who have not committed a serious crime — despite its stance to focus on dangerous criminals.

Requests that an immigrant be held are sent to local law enforcement by the U.S. Immigration and Customs Enforcement, or ICE. The agency knows who is being booked into local jails because of an information-sharing partnership between ICE, the Federal Bureau of Investigation and local jurisdictions.

The notices request that the person be jailed for an extra two days, excluding weekends and holidays, so that ICE can initiate an investigation and take the person into custody.

But immigrant rights advocates say ICE has made mistakes in the past, incarcerating U.S. citizens, people who have not committed any crimes, or those arrested on misdemeanors.

"They do it in a dragnet manner without first doing the investigation upfront, sometimes before a local district attorney has even signed off on the charges. So it results in the unjust incarceration of a lot of people who are not deportable at all, or who are not found guilty in the criminal process," said Kate Desormeau, an attorney with the American Civil Liberties Union.

In recent years, California, Connecticut and more than a dozen jurisdictions around the country have stopped or limited their compliance with the so-called immigration detainer requests. Lawmakers in Massachusetts and Maryland are considering similar legislation. On Wednesday, the mayor of Philadelphia signed an executive order limiting the use of such holds.

ICE has said that the requests are optional. The detainers generally are not accompanied with a warrant.

But many local law enforcement agencies say they have treated them as orders because the requests cite federal regulation, which states that a law enforcement agency "shall maintain custody of an alien" once a detainer request has been issued.

"The fact that the detainers contain both language of request and command has led to conflicting interpretations as to whether the immigration detainers provide legal authority for the continued custody of the people named in the detainers," Clackamas County Sheriff Craig Roberts wrote in a letter announcing the suspension in the use of detainers.

Roberts changed his policy after a U.S. District Court judge last Friday found the detainers are "requests" that do not provide the necessary legal basis for the jail to hold a person in custody after charges are resolved — and consequently, that in March 2012, the county violated Maria Miranda-Olivares' rights under the 4th Amendment by prolonging her incarceration without probable cause.

The woman, who was found guilty of contempt of court and sentenced to 48 hours in jail, was incarcerated for more than two weeks due to the ICE hold, even though she was eligible for pre-trial release upon posting bail and after her release from state charges. A hearing will determine how much the county must pay Miranda-Olivares in damages.

The ruling has led sheriffs in Oregon's Multnomah, Washington, Marion and Deschutes counties to suspend the use of immigration holds. The regional jail that serves Hood River, Wasco, Gilliam, and Sherman counties will also no longer comply with ICE detainer requests.

The Clackamas County case follows a similar case in Philadelphia, where the 3rd U.S. Circuit Court of Appeals ruled last month that state and local law enforcement authorities are not required to comply with requests from ICE to hold people on detainers without probable cause. The ruling, which involved a U.S. citizen, also recognized that states and localities may share liability when they participate in such detentions.

And in another case in Rhode Island involving a naturalized U.S. citizen, the district court issued a decision reaffirming that detainers don't justify warrantless imprisonment and allowed the immigrant's lawsuit against federal and state defendants to proceed.

"These rulings have dispelled any lingering uncertainty on whether localities can say no to ICE detainers," Desormeau said. "So jurisdictions that have been sitting on the sidelines may now act to limit their use. Otherwise, they're inviting legal liability."

Based on reporting by the Associated Press.