Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Relatives of a 30-year-old mother from Vermont who died in police custody five months ago claim authorities ignored her "desperate pleas to be taken to a hospital" — consequently failing to provide her lifesaving care, according to a federal lawsuit filed in Massachusetts this week.

Madelyn Linsenmeir was "a victim of the opioid crisis, having developed substance use disorder after using prescription opioids in high school," say her relatives in the lawsuit against the city of Springfield and the Hampden County Sheriff's Department.

She was arrested late Sept. 2018 by police in Springfield, Massachusetts, on a probation-related arrest warrant.

Video of Linsenmeir after her arrest, which was obtained and posted by the ACLU, shows her asking for water and telling officers she felt a chest pain and "might need to go the hospital.”

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Instead, Linsenmeir was booked as an inmate at the Western Massachusetts Regional Women's Correctional Center, the complaint says.

The family alleges Linsenmeir repeatedly told jail staff that she felt sick and needed medical attention but was told “the situation was her own fault for using drugs,” the lawsuit claims.

Linsenmeir was still in custody when she was taken to a hospital on Oct. 4, 2018, after staff saw she was “in severe distress constituting a 'Medical Emergency,'” the complaint alleges. She died days later of a treatable heart infection at the hospital, the lawsuit says.

“Our family is heartbroken to have lost our beloved girl and deeply troubled by her unnecessary, preventable death,” said the family in a statement. “In Maddie’s name, we will continue to advocate for the humane treatment of people everywhere who struggle with substance use disorder, especially those who are at the mercy of a criminal justice system that is clearly not equipped to respond to the opioid crisis.”

The American Civil Liberties Union of Massachusetts and Prisoners' Legal Services of Massachusetts are representing the family in the case.

“Substance use disorder is a disease, and it is legally and morally indefensible for law enforcement agencies to deny appropriate medical care to prisoners with substance use disorder based on prejudice and stereotypes,” said Elizabeth Matos, executive director of Prisoners’ Legal Services, in a statement.

The Hampden County Sheriff's Department told The Associated Press in an emailed statement that it cannot comment on a specific death but “always aims to provide the best healthcare available” to those in its custody.

Carol Rose, executive director of the ACLU of Massachusetts, said in a statement that "people in jails and prisons do not forfeit their right to adequate, timely health care just because they are behind bars — and people suffering from addiction deserve just treatment.”

“There is no excuse for Madelyn Linsenmeir’s mistreatment and subsequent death,” she said. “Police are accountable for the safety, health, and well-being of all people in custody."