PROVIDENCE — A federal judge has dismissed a lawsuit filed by the Rhode Island Affiliate of the American Civil Liberties Union that challenged the detention of 14 Guatemalan nationals for possible immigration violations after the van they were in was stopped by a state trooper for a minor traffic infraction on Route 95 in Richmond.

All turned out to be in the United States illegally.

The ACLU said yesterday it will appeal.

U.S. District Judge Mary Lisi ruled that Thomas Chabot acted lawfully during the July 11, 2006, stop, in which the trooper asked passengers in a van for identification, then sought proof of citizenship among the people who had no ID, and then contacted immigration officials when most could not provide the information.

The driver, Carlos E. Tamup, who was not wanted and turned out to have a valid driver’s license and registration, was stopped, according to Chabot, for changing lanes without using a turn signal. Tamup had to act as a translator for many of the occupants.

ACLU Director Steven Brown said the organization will appeal because “this was a classic case of racial profiling” when the state bans the practice.

Judge Lisi, in a 20-page decision available on the ACLU’s Web site (riaclu.org), rejected claims that the stop was tainted, that the driver should not have been repeatedly searched, and that the trooper had no business acting on his suspicions that the passengers in the van were illegal aliens.

She said a 2005 U.S. Supreme Court case found that “an officer did not need independent reasonable suspicion to question an individual about her immigration status during the execution of a search warrant,” and the rule applied in this case as well.

Inquiring about a person’s name, date and place of birth, or immigration status does not constitute unreasonable search and seizure under the Fourth Amendment, she said.

Lisi said the trooper had a right to inquire about immigration status after all but four of the occupants of the van “had failed to provide any identification and Chabot’s suspicions reasonably escalated.”

She said that under two Supreme Court decisions, “It is permissible for officers to inquire into the immigration status of individuals without triggering the Fourth Amendment or requiring independent reasonable suspicion.”

The men in the van said they were going to work in Westerly, and immigration was contacted only after learning that most people in the van lacked documentation.

“Based on how events unfolded, Officer Chabot’s attention and his suspicion shifted from the original traffic citation to other concerns, namely to potential violations of federal immigration law. Such a shift in focus is neither unusual nor impermissible,” the judge ruled.

According to the decision, the trooper then contacted the Office of Immigration and Customs Enforcement, which instructed state police to bring the group to ICE headquarters in Providence.

Attorney General Patrick C. Lynch issued a statement yesterday focusing on the fact that Chabot was acting under the instruction of ICE.

“While the law enforcement community is sensitive to and must remain sensitive to immigration issues, they must also be able to do their jobs,” said Lynch.

The suit, filed on behalf of 11 of the van’s occupants, argued that the state violated the Racial Profiling Prevention Act and that discrimination played a role in the traffic stop and subsequent events.

Brown said state law prohibits the continued detention of vehicles during traffic stops unless there is a suspicion of criminal activity.

In a statement, the organization said Lisi’s ruling “does not explain what suspected criminal activity was involved, since [a] mere presence in the country illegally is not a crime.”

The ACLU has also argued that Tamup, the driver, had been subjected to repeated pat-down searches, which were improper.

The trooper, Lisi argued, “had reasonable suspicion to believe that [the people in the van] had violated federal immigration law” and Chabot had no way of knowing whether anyone in the van posed a threat — since they had no identification — and whether some type of weapon had been exchanged during the time he was away from the van making checks.

“Under the totality of the circumstances that confronted him,” the judge said, “Chabot’s pat-down searches of Tamup were justified and therefore pass constitutional muster.”

gemery@projo.com