Eric Alvarez remembered what it felt like to hear his fiancée was coming home from prison: overwhelming relief.

Alvarez has heart trouble and he's struggled to take care of his four kids and his fiancée's daughter through their long separation. When Eva Cardoza returned from the federal correctional institution in Danbury, Conn., she shouldered a lot of burdens.

"She was doing everything at home. She was cooking, cleaning, taking care of the kids, helping them with homework," Alvarez said.

More than 11,000 people like Cardoza have been released from federal prison in the last couple of years, to ride out the pandemic at home, often with their families and loved ones. But that situation can be precarious.

In June 2021, Alvarez and Cardoza took a 90-minute cab ride into the Bronx, so she could meet with staffers in charge of her supervision. Cardoza, who had tested positive for marijuana, never came out of the building. Alvarez ended up forking out $433 to cover the hours the taxi meter ran as he waited in vain.

Cardoza's return to prison turned the family upside down. She's now been back at Danbury for 14 months. Alvarez said she never got the chance to explain herself or challenge that single positive drug test.

"That's just mind boggling to me," Alvarez said. "Where is the judicial system? Where is the fairness? Where is the 50-50? I don't see it."

Less than 0.2% of the people released committed new crimes while they were out

This week, the Bureau of Prisons told NPR that 442 people who were released during the pandemic have now returned to prison. Only 17 people out of more than 11,000 who were released committed new crimes, mostly drug related ones, while they were out. More than half, some 230 people including Eva Cardoza, got sent back for alleged alcohol or drug use. Other cases involved technical violations.

Sakira Cook of the racial justice group Color of Change explained what that means.

"It could be as simple as failing to answer the phone when your probation officer calls you. It could be as simple as the ankle monitor giving an incorrect signal about your location," Cook said.

Cook has personal experience with that last problem: a relative recently left federal prison on home confinement, only to get an ankle monitor that didn't work. Fortunately, she said, the probation officer understood the situation.

Kevin Ring advocates for people in prison and their families at the group FAMM, formerly known as Families Against Mandatory Minimums.

"In a normal circumstance, somebody who violates the terms of their home confinement is sent back to the halfway house or to prison, but the stakes are much lower," Ring said. "They're only going back for a month or two."

But some of the people released from prison under the bipartisan pandemic legislation called the CARES Act have years remaining on their prison terms.

"Is it really worth sending people back for years because they missed a phone call or they had alcohol in their urine?" Ring asked.

Hoping for due process as a judge rules the current procedures are unconstitutional

Most of the monitoring of people on home confinement is being done by private contractors, said Quinnipiac University School of Law professor Sarah Russell.

"There can be a lot of room for miscommunications and misunderstandings," Russell said.

Russell said that's all the more reason to ensure due process rights for people at risk of being sent back: the opportunity to see the evidence against them and to have a hearing before a neutral arbiter.

Last week, one of Russell's clients won those rights in court. The decision by Judge Omar Williams is the first in the nation to hold that the current process for returning people to federal prison after home confinement is unconstitutional.

Russell said her other clients — moms with young children — are still nervous about having to leave their lives behind unexpectedly.

"My real hope is that this gets addressed at the national level through the Bureau of Prisons and through the Department of Justice," Russell said. "They have a real opportunity to set clear procedures and criteria."

More lawsuits from people returned to prison are under way. The Bureau of Prisons said it can't talk about that pending litigation. But it is considering a new federal rule to make the process more clear.

For Eric Alvarez, 46, that can't come too soon. He's been diagnosed with colon cancer — the same disease that took his uncle years ago.

"And my heart is not up to par to take this kind of abuse and now I'm going through it on my own," he said. "It's just I'm afraid that I'm going to die alone."

Alvarez talks to his fiancée in prison on the phone, or with video calls. But he said it's not the same as having her home.