The circumstances of many of the record number of deaths in US immigration custody under the second Trump administration have left loved ones often searching in vain for answers amid a lack of transparency over key investigations.

Immigration and Customs Enforcement (ICE) reports mandated by Congress, autopsy reports and 911 calls collected by the Guardian raise questions about the quality of medical care, allegedly inadequate or haphazard responses to emergencies, and contraction of diseases and infections inside detention facilities that in some cases contributed to detainee deaths.

Families and their attorneys, as well as immigration advocates and Democratic elected officials have struggled to navigate a bureaucratic labyrinth of multiple federal agencies, local medical examiners and coroners, walled-off detention facilities, and, in some cases, local law enforcement, to obtain answers about the many deaths.

Veronica Escobar, a Texas congresswoman, said the maze of local and federal agencies and facilities, as well as private contractors operating detention facilities is a “massive problem”.

“It’s a quagmire created by choice … This is not how things should work,” she said.