The mother of a man who died in agony in Immigration and Customs Enforcement custody is preparing to sue the United States government for his death.

According to previously unreported court documents reviewed by The Daily Beast, the mother of an undocumented immigrant who died of bacterial meningitis is preparing for civil action related to his death. On June 4, Honduran native Martina Blasina Romero petitioned a federal judge in the Southern District of Texas to authorize depositions of the people who were held with her son, Ronal Francisco Romero, and know about the health collapse he experienced in his last days.

Border Patrol agents arrested her son on May 9, 2018, when he tried to enter the United States illegally. They held him at a Customs and Border Protection detention facility for about six days before turning him over to ICE custody. At about 2:30 a.m. on May 16, the authorities sent him to a local hospital. Less than 24 hours later, he was pronounced dead.

Katie Shepherd of the American Immigration Council said health care in CBP facilities—where Romero first got sick—is severely lacking.

“The access to medical care in the CBP holding facilities is virtually nonexistent,” she said.

At least 27 people have died in ICE custody since 2015, according to the American Immigration Lawyers Association.

At his mother’s request, Dr. Kris Sperry—formerly Georgia’s chief medical examiner—performed an independent autopsy and found that he died of bacterial meningitis, which started with an ear infection and spread to his brain. He also experienced renal failure and ketoacidosis, according to the court filings. County authorities separately performed their own autopsy.

“Both autopsies suggest Mr. Romero likely died an agonizingly slow and excruciatingly painful death,” the court filings said.

“Based on the information currently available, Dr. Sperry concludes that Mr. Romero would have been intensely, visibly ill and in severe pain for several days prior to his admission to VBMC on the afternoon of May 15, 2018,” the filing continued. “Mr. Romero’s observable symptoms of illness would have included intense ear and head pain stemming from the pressure caused by the bacterial infection and growing build-up of pus in his right middle ear; clammy appearance and skin discoloration; fever; dehydration; and potential nausea and vomiting.”

The medical examiner also found that Romero would have appeared disoriented, confused, and nonresponsive as his illness progressed, “such that his mental deterioration would have become immediately obvious to any observer.”

Romero’s mother’s lawyers are now fighting time: looking to talk to the people familiar with Romero’s condition before they become difficult to find—deported, moved to far-flung detention centers, or released into the United States on their own recognizance. The lawyers are asking for CBP and ICE to answer questions about which people were housed with Romero. With that information, they hope to ask those people how he appeared as his health deteriorated.

They have notified DHS and ICE lawyers, as well as the U.S. attorney for the Southern District of Texas, of the petition’s filing. The lawyers are looking to have a hearing within three weeks on whether or not they can depose the people who were detained with Romero.

Advocates have long decried the health care problems associated with the immigration detention system.

“This is a longstanding and persistent issue,” said Bob Libal, who heads the anti-detention group Grassroots Leadership. “This is an agency that increasingly is not interested in the health and welfare of people in its custody and it’s also an entity that has expanded so rapidly over the last 15 years that providing even the most basic of safety for people who are in its custody is something that is difficult.”

And Silky Shah, who heads the Detention Watch Network, said cases like Romero’s are not isolated.

“The thing that’s been really clear is that there are consistent delays in medical care that then lead to a death, meaning that if things were addressed immediately then the death could be preventable,” she said. “In that sense, I think moving toward having more wrongful death lawsuits is an important way to put a check on the system. We’re watching, we’re paying attention.”