Court filings obtained by the PBS NewsHour this week reveal new details about the separation of migrant families at the U.S.-Mexico border and the long-term trauma it could be inflicting on thousands of children.

The new court documents, filed by the Southern Poverty Law Center and the private law firm Covington and Burling, feature three families that allege they were separated at the southern border between 2017 and 2018. They argue the government’s separation violated the constitution and “norms of basic human decency.” This comes months after a similar suit brought by two families, also through the SPLC and Covington and Burling, in April.

These separations occurred before a court order from June 26, 2018 that required the government to stop the practice.

According to the American Civil Liberties Union, which reviewed government data as part of ongoing litigation, migrant children are still being separated from their parents. A total of 911 children were separated from their families at the southern border between June 28, 2018, and June 29, 2019, the ACLU said.

The inspector general for Health and Human Services warns that “thousands more” could have been separated as far back as 2017, and in early 2018, prior to government tracking.

Both of those numbers are on top of the 2,737 children separated from their families during a six-week period ending in June 2018, when the Trump administration was routinely separating families who arrived in the U.S.

The newest claims provide insight into what exactly happens during the moments of separation, the chaos individual families faced when trying to locate and connect with their children, and the lasting harm they suspect has been done to their young children.

READ MORE: What I saw happening at the U.S.-Mexico border

The government did not respond to a request from the PBS NewsHour for comment on these cases. The cases are pending, and the government has six months to either respond, or reject the administrative claim, opening the door for the families to potentially sue in federal court.

Here are the stories as they have been presented in court documents prepared by their lawyers, and how experts are responding.

The families’ stories

Case #1: M.C.L. and A.C.R.

The separation:

A father, identified in court filings as M.C.L., was separated from his 7-year-old son, A.C.R., in November 2017, after presenting themselves with identification documents to officials at a legal port of entry in Arizona in order to seek asylum in the U.S.

“M.C.L. was shocked. He told the officer, no, that A.C.R. was his son and that the government could not take him away. The officer approached A.C.R. who began darting from one place to another in an effort to avoid the officer. M.C.L. could see the fear in A.C.R.’s eyes as he tried to avoid the officer. After a few seconds, the officer gave up,” the court filing states.

Two days later, another officer told the father that the separation was going to happen. After waiting for two hours, officers came for M.C.L. and A.C.R. They stood on each side of M.C.L., grabbed his arms and forced him to sit on a bench. Officers then took away his son.

M.C.L. “heard A.C.R. crying in despair until A.C.R.’s cries became distant and he could not hear his son anymore,” the document states.

During separation:

M.C.L. was moved to a federal detention center and spent weeks trying to get information about his son. When he initially attempted to find A.C.R., he was told there was no record of his son being in ICE custody, causing him “extreme shock and pain.” More than a week after their separation, he was told his son had been moved to a government shelter in New York. After approximately nine days, M.C.L. got a phone number but had no money to call him.

When they were finally reconnected, “the case manager put A.C.R. on the phone, A.C.R. just cried and was unable to speak,” the court filing reads. He was told his son cried constantly in custody.

M.C.L. says his intention to seek asylum in the U.S. changed once his son was taken from him — his priority was getting A.C.R. back.

The father signed deportation papers because an officer told him that his son would be returned to him in Guatemala immediately after he was deported. He was deported in January 2018. After months of no communication from A.C.R.’s case manager, his parents feared they would never see him again. Seven months later, on July 26, 2018, A.C.R. was sent back to Guatemala as well.

After separation:

The father said it wasn’t long before he and his wife realized something had changed in their son.

“A.C.R. now seemed to live in a perpetual state of fright. He was generally reluctant to talk to M.C.L. and his mother, and in particular, did not want to talk about his time in the United States,” the court filing states.

“A.C.R. now seemed to live in a perpetual state of fright.”

M.C.L. says his son wakes up in the middle of the night sobbing, struggles with being back in school, and becomes upset very easily, “unable to cope with things that most children his age would find trivial.” He cries when asked to do a chore, refuses to eat and often cries to himself.

“Sometimes he cries for no apparent reason…When other children ask him if he has been to the United States, he breaks down in tears.”

M.C.L. says he, too, is tormented by memories of the separation.

“He cannot forget A.C.R.’s cries as he was carried away by immigration officers. [He] feels guilty and saddened at the realization that his son is not the same happy boy that he was before the separation. M.C.L. is also tormented by the fact that he may never know exactly what happened to A.C.R. during the eight months that they were separated.”

Case #2: H.P.M and A.P.C.

The separation:

A father, H.P.M., was separated from his 6-year-old daughter, A.P.C., between May 12 and May 15 in 2018, after crossing the U.S. border into Arizona.

A Border Patrol agent immediately approached H.P.M. and his daughter, and took them to a detention center, disclosing neither the facility’s name nor location. The agents then took the migrants’ outer garments and gave them each an aluminum blanket before escorting them to a locked, windowless room. H.P.M. described the room as an “hielera” or “icebox” due to the “three large vents” in the room “spouting freezing air at all times.”

After what H.P.M. thought was two days in the cold and constantly lit room with very little food, A.P.C. told her father that she was feeling unwell and fell asleep, and became “almost non-responsive.” H.P.M. tried to get an officer’s attention, but “officers who walked by only ignored him.”

On what H.P.M. believed to be the third day of their detention, an officer gave the father a bar of soap and instructed him to give his daughter a bath. A.P.C. was so weak she could barely stand. After the bath, H.P.M. saw a group of officers waiting for them outside the bathroom.

One “officer explained that the children were being taken to a place for children about half an hour away,” the court documents state.

“A.P.C. tried to run closer to H.P.M., but an officer put his arm in front of her and pushed her back. A.P.C. threw herself to the floor and began crying and screaming. H.P.M. felt devastated but did not know what to do to prevent the officers from taking A.P.C.”

During separation:

The father was moved to another detention center, and then another, and at both places he asked several officers for information about his daughter. Officers ignored his questions or said they knew nothing about her circumstances.

H.P.M. met with an Immigrations and Customs Enforcement (ICE) officer, who asked him if he wanted to be deported. HPM said no and that he was still waiting to be reunited with his daughter.

“The officer appeared confused and asked H.P.M. for his daughter’s name. H.P.M. provided her name and showed the officer her birth certificate, which he carried with him at all times. The officer turned to his computer and began typing. After a few minutes, the officer said A.P.C. was in the country, but that she was an unaccompanied minor who had arrived in the United States alone, without a mother or father. The officer told H.P.M. that she would be put up for adoption,” the court filing said, and he began to think he would never see her again.

After nearly two and a half weeks, the father was able to speak with his daughter. When she got on the phone, she began to cry and asked: “Why did you leave me?”

When she got on the phone, she began to cry and asked: “Why did you leave me?”

The girl had been moved from Office for Refugee Resettlement custody to transitional foster care in Michigan. Authorities who performed a routine review of the girl’s case at the time found that her foster mother gave her melatonin — a hormone used to treat insomnia — because the girl woke up in the middle of the night and cried for “long periods of time.”

In early June, after H.P.M. was transferred to his third detention center since being separated, several officers told him to sign papers that were in English with no Spanish translation. One officer told H.P.M. that if he didn’t sign, he “would never get his daughter back” and another officer said that after H.P.M. signed, he “would be taken to the airport, where his daughter would be waiting for him,” the court documents said.

When H.P.M. was deported in early June of 2018, his daughter was not there to join him. A.P.C. was sent back to Guatemala City more than two months later, on Aug. 30, 2018.

After separation:

H.P.M. said he felt happiness and an “enormous sense of relief” when he saw A.P.C. again, but his daughter “simply stood before him and his wife with a blank stare on her face.”

She then recognized him and gave him a hug but said nothing. The girl’s mother called her over, but A.P.C. appeared not to recognize her or her brother.

After returning home, the girl “refused to eat” and “cried for hours, both during the day and at night.”

“Whereas before she was a happy and adjusted child, who was outgoing, friendly, and trusting of adults, she is now quiet, distant, and still cries easily,” her parents explained in the court documents. A doctor recommended that she receive therapy, but H.P.M. said he could not afford to pay for it.

Case #3: R.Z.G. and B.Z.E.

The separation:

The father, R.Z.G., was separated from his then 9-year-old daughter, B.Z.E., around Nov. 15, 2017. R.Z.G. and his daughter B.Z.E., who are part of the Mam indigenous tribe in Western Guatemala, had presented themselves to agents on Nov 13 at a legal port of entry in Nogales, Arizona, seeking asylum.

They were taken to a windowless, locked and “overcrowded” room that was made “almost entirely of cement.” Two times a day, the officials would give them burritos to eat. Sometimes, the burritos were still frozen and the officials would throw them on the floor.

On the second day of their detention, agents transferred R.Z.G. and B.Z.E. to another facility.

The next day, officials told R.Z.G. that he “needed to go with them because he had court.”

“R.Z.G. walked over to the door of the room and B.Z.E. jumped up to go along with him. But as soon as R.Z.G. walked out of the room, the official closed the door behind him before B.Z.E. could follow her father. R.Z.G. saw B.Z.E. through the window of the door and heard her screaming ‘Papá, Papá!’ Flailing and crying inside the room, B.Z.E. begged to go with her father. Two officials grabbed R.Z.G. and began to cuff his hands and feet. R.Z.G. asked the officials, ‘Why are you taking me away? Why are you separating us?’ but he was not given any information. R.Z.G. was not permitted to hug B.Z.E. or say goodbye before he was forced to leave her,” the court document said.

RZG was taken to another detention center, with about 20 other men.

During the separation:

After several days, the father finally was able to connect with his daughter’s social worker and speak to his daughter on the phone. They both cried as they spoke.

The daughter told her dad that she had been taken to New York. She said she was fine, but that she wanted to be with him. Their phone conversation was cut off after two minutes.

The father was able to speak with his daughter again over the phone a week later. That is when he learned that his 9-year-old daughter had been beaten by an immigration official after they were separated, leaving purple bruises on her leg.

“R.Z.G. listened as his nine-year-old child recounted her distress on the night they were separated, which left her inconsolable. B.Z.E. had watched through the glass window in the door as her father was handcuffed, shackled and taken away from her. All of a sudden, she was alone and terrified. She had no idea what would happen next, and she screamed and cried uncontrollably to be able to go with her father. B.Z.E. told R.Z.G. that an immigration official wearing a uniform threatened her and said that if she did not stop crying, the official was going to hit her. The official then removed her belt and beat B.Z.E. on the arm and leg several times because B.Z.E. could not stop crying,” the court document detailed.

The daughter said the day after she was beaten, she was taken and “pushed forcefully” into a car and put on two flights to New York, feeling “scared and alone.” She was transferred from the Office of Refugee Resettlement custody to a foster home. Her first language being Mam and only understanding “some” Spanish, it was very difficult for her to communicate with anyone.

After separation:

The father was deported back to Guatemala in December without his daughter. She was returned to their country on July 26, 2018, after being separated from her father for 253 days.

After returning, the girl’s family said she “prefers to stay at home with her mother and her brothers…does not socialize with other children at school, and it has taken constant encouragement for her to play with her cousins,” the court filing said.

The girl’s mother struggles with anxiety and depression and her father is “easily startled and suffers from anxiety, constantly worrying that something bad could happen.”

What medical experts say

Medical experts have repeatedly warned about the potential long-term effects of child separation.

Toxic stress syndrome, a condition that occurs when a child is exposed to trauma for a prolonged period of time, can hinder brain development, causing emotional and mental issues for years. Disruption of brain development during these early years also lead to “unhealthy behaviors” later, like smoking and illicit drug use later on.

Cmdr. Jonathan White, a health official at the Department of Health and Human Services, told federal lawmakers earlier this year that he warned the White House about the potential mental health effects of separating children from their parents when President Donald Trump raised the idea shortly after his inauguration.

Jack Shonkoff directs the Center for the Developing Child at Harvard University and said experiences like those of the three migrant children suggest that from a child’s perspective, the trauma of family separation is no different than being kidnapped. And for parents, the helplessness of having their child ripped from them and gone for weeks or months leave long-lasting marks on the physical, mental and emotional health of a family.

“That goes against everything thing we know about meeting the basic needs of the child,” Shonkoff said.

Arguing over how clean the facilities are, where these children are held, and how much nutritious food they eat, misses the point when they are denied any contact with their caregivers, he said.

“From a child’s point of view, these children are kidnapping victims, and they’re kidnapping victims until somebody saves them and brings them back home,” he said.

While therapy can help reduce the effects of toxic stress, medical professionals say prevention is most important.

More than a year after the Trump administration’s major push to separate families, child advocates point out that because it is not clear how many children have been separated from their families, there is no way of knowing how widespread the trauma is.

What government officials say

Immigration officials did not respond immediately to questions from the PBS NewsHour about the cases outlined in the latest court filings.

At a congressional hearing earlier this month, acting Homeland Security Secretary Kevin McAleenan said “the vast majority” of migrant families are kept together when they are taken into U.S. custody.

The administration has said it does take children from their parents in rare circumstances when the parent is a threat to their child’s well-being.

Government documents show the reasons for the separation spanned a wide range from assault to marijuana possession to, in at least one case, a traffic incident.

What advocates say

But immigration advocates say the U.S. government is using minor offenses as an excuse to continue its policy of child separation.

“Little babies and toddlers are being separated on the pretext that the parents are a danger to them,” ACLU lawyer Lee Galernt told the PBS NewsHour on Tuesday.

In hopes of deterring the practices, the ACLU is asking a court to clarify the standards that can be used to justify children being separated from their parents.

Laura Santhanam contributed to this report.