Two teenage sisters fleeing Guatemala waved a U.S. Customs and Border Protection truck for help after they got lost trekking across the Texas desert.

The Assault:

The sisters, 19 and 17, were forced to strip and sexually assaulted by a Border Patrol officer after being taken to a closet in the Presidio intake office in July 2016. On Tuesday, Attorneys for the American Civil Liberties Union of Northern California filed legal claims against the Department of Homeland Security on behalf of the sisters who are now living in Fresno with their mother.

The claims describe the alleged molestation by the Border Patrol officer, whose identity remains unknown. Each sister is seeking $750,000 in compensation.

The older sister said: “What happened in that closet has caused me so much pain and sadness. I’m telling my story because I don’t want anyone else to go through this.”

Out of fear of retribution, the sisters’ identities were shielded by their attorneys.

The elder sister said in her claim and statements that the girls fled tyranny in Guatemala. She knew that arrest and deportation were possible when they crossed the border, but she believed they would be safe.

But, on the night of July 11 they were left in a holding cell with the Border Patrol officer inside the Texas intake office, who took the older sister to a windowless closet, according to her statement.

While in the closet, he ordered her to remove her sweater, shirt, tank top and bra; she successfully pleaded to keep her bra, the officer fondled her breasts. He then ordered her to remove her pants, leggings and underwear; she begged to keep the underwear on, but he pulled it down and touched her genitals with his hands. She realized it wasn’t a weapons check but a sexual assault. The officer returned to the cell and took the young sister, and he repeated the conduct with her.

Angélica Salceda, ACLU of Northern California staff attorney said: “CBP must be held accountable for its officer’s sexual abuse of these vulnerable victims. There has been no criminal prosecution against the officer involved. CBP is not above the law, and its abuses of power must not be tolerated.”

Customs and Border Protection representative said they can’t comment on an active lawsuit, adding: “We take allegations of misconduct seriously and there is no room in CBP for the mistreatment or misconduct of any kind toward those in our custody. We do not tolerate corruption or abuse within our ranks”

A zero tolerance policy is adopted by the department, prohibiting all forms of sexual abuse and assault in its custody. In 2014, it adopted a rule forbidding male officers to pat down female detainees.

Not A Unique Case:

The vast majority of complaints involving Border Patrol agents on the Southwest border resulted in no disciplinary action, according to a 2014 Los Angeles Times investigation. They obtained documents suggesting little accountability for alleged beatings, sexual abuse and other mistreatment of detainees.

An investigation was launched by the Department of Homeland Security’s Office of Inspector General after the sisters reported the conduct to another CBP officer an hour post the alleged assaults.

Criminal charges against the officer have not pursued by federal authorities so far, according to ACLU attorneys, and they do not know if any disciplinary action was taken. They’re unsure of the Border Patrol officer’s identity, but the sisters pointed him out to other officers when reporting the attacks.

Sexual misconduct allegations against the Border Patrol aren’t unusual. At least 21 Customs and Border Protection officers had been indicted or pleaded guilty to sexual offenses according to a 2015 CBS News investigation.

The agency’s former head of internal affairs revealed that from 2012 to 2014 more than 35 sexual misconduct cases were pursued against agents.